Visual Mode: fixed a problem where texture skewing didn't work correctly for textures scaled through sidedef properties. Fixes #985

Visual Mode: added support for GZDoom style texture skewing

- fixed a rare condition where skewed mid textures were not clipped correctly
- fixed a problem where translucent mid textures were not skewed correctly
- fixed a problem where sprites were skewed unintentionally

Visual Mode: fixed a problem where offsetting the middle texture of double sided lines would not work under certain circumstances. Fixes #702

Removed lots of unnecessary casts to float of the Math methods. Also removed some other minor implicit casts

- Textures will now wrap correctly in visual mode when the flag of the Line_SetIdentification special is set in Hexen format. Fixes #271

- Improved support for auto aligning scaled textures

Fixed, Script Editor: resources navigator was always loading the first WAD lump with matching name when trying to open any of several WAD lumps with matching names.
Reverted, Visual mode: looks like all additional cases of displaying sky hack added in r2755 were actually undefined engine behaviors, not the "proper" shy hack... Reverted implementation to the wiki definition of the sky hack.

Updated, Visual mode, UDMF: "Change Texture Scale" actions now take camera and texture angles into account when used on floors/ceilings.
Changed: "+++" and "---" prefixes are now incremented on the first step instead of the second when used in any numeric inputs, which support prefixes, except action arguments.
Fixed, Visual mode, UDMF: texture offset/scale/rotation changes were applied several times when used on several 3d-floor floors/ceilings linked to the same control sector, when using "Move Texture Offsets" / "Change Texture Scale" / "Rotate Texture CW/CCW" actions.
Updated ZDoom ACC (DamageActor).
Updated ZDoom_ACS.cfg (DamageActor).

Fixed several cases when certain texture manipulation-related actions caused a crash when performed on not-yet-loaded textures.

Visual mode: modified sidedef texture UV calculations to use integral linedef length to match (G)ZDoom way of rendering them.
Visual mode, UDMF: "Auto-align textures" actions now use integral linedef length when calculating texture offsets.

Added, Visual mode: added "Toggle Alpha-based Texture Highlighting" action. When enabled, 3d floor textures and middle textures on double-sided lines will be highlighted only when the crosshair points at a non-transparent pixel.
Changed: multi-part sectors are now better preserved after drawing new lines.
Changed, TEXTURES parser: patch loading errors are now ignored for textures with "NullTexture" option.
Changed, Game configurations: changed default door action arguments to better match vanilla ones.
Fixed, Actions: in some cases keyboard shortcuts involving Ctrl/Alt/Shift modifier keys were displayed incorrectly.
Fixed(?): probably fixed inability to save map wad in Slade 3.
Updated ZDoom_ACS.cfg.
Updated ZDoom_DECORATE.cfg.
Updated ZDoom ACC.

Fixed, Visual mode: alpha-based texture picking didn't work correctly on HiRes images.
Fixed, Visual mode: fog density was calculated incorrectly for things lit by dynamic lights.
Fixed, Edit Sector window, UDMF: "Fade" and "Light" color pickers initial values were incorrect when displaying mixed values.
Fixed, Edit Thing window, UDMF: "Color" color picker initial value was incorrect when displaying mixed values.

Added, Visual mode: "Raise/Lower Floor/Ceiling to adjacent Sector" actions now take surrounding 3d floors into account.
Added, Visual mode: highlight/selection based on texture alpha now works on 3d floors.
Changed, Game configurations, TranslucentLine:208 action: renamed the second argument from "Translucency Amount" to "Opacity".
Internal, documentation: updated udmf_zdoom.txt.

Fixed, Visual mode: in some cases ceiling glow effect was interfering with Transfer Brightness effect resulting in incorrectly lit sidedef geometry.
Fixed, Visual mode: UDMF sidedef brightness should be ignored when a wall section is affected by Transfer Brightness effect.
Fixed, Visual mode: any custom fog should be rendered regardless of sector brightness. 
Fixed, Visual mode: "fogdensity" and "outsidefogdensity" MAPINFO values were processed incorrectly.
Fixed, Visual mode: in some cases Things were rendered twice during a render pass.
Fixed, Visual mode: floor glow effect should affect thing brightness only when applied to floor of the sector thing is in.
Fixed, TEXTURES parser: TEXTURES group was named incorrectly in the Textures Browser window when parsed from a WAD file.
Fixed, MAPINFO, GLDEFS, DECORATE parsers: "//$GZDB_SKIP" special comment was processed incorrectly.
Fixed, MAPINFO parser: "fogdensity" and "outsidefogdensity" properties are now initialized using GZDoom default value (255) instead of 0.

Updated skybox model to better match GZDoom's skybox. Also the sky texture was flipped horizontally.
Fixed, Visual mode: "Select with the same texture" action is now able to select sidedef parts only visible because of slopes.
Fixed, Visual mode: skybox texture was not updated after using "Open map in current wad" action.
Fixed, Visual mode: in some cases Visual camera was placed below sector's floor when "Sync camera position between 2D and 3D modes" setting was enabled.
Fixed: numeric thing flags with inverted UDMF flag defined in "thingflagstranslation" Game configuration block were lost when copy-pasting a thing.
Fixed, command line arguments: fixed a crash when loading a map from a wad with existing .dbs file.

Fixed, Map Analysis mode, "Check stuck things" check: rewritten parts of the flags checking logic to allow more accurate flag checks.
Fixed, Map Analysis mode: fixed a crash when trying to dissolve an invalid sector when one of it's linedefs referenced it on the both sides.
Fixed, Sectors mode: fixed incorrect undo description when deleting sectors.
Internal: joined declaration and assignment of some more variables.

Visual mode: rewritten most of the 3d floor clipping and light/color assignment logic. As a result, 3d floors should look much closer to what's seen in GZDoom.
Fixed, Visual mode: glow effect was not updated when changing sector textures using the "Select Texture" action.
Browse Textures/Flats window: when textures list is focused, you can now start typing to change the Filter.

Added "Paste Properties Special" actions in "Classic" and "Visual" categories. They work the same way as "Paste Special" action.
Added: "Copy Properties", "Paste Properties" and "Paste Properties Special" options are now shown in the Edit menu if current classic mode supports them.
Changed, Paste Properties Special window: only options relevant to current map format are now displayed.
Changed, Paste Properties Special window, UDMF: all UI-managed options are now available.
Fixed: MAPINFO parser was unable to process "include" directives.
Fixed, General interface: selection info was reset to "Nothing selected" after few seconds regardless of current selection.
Fixed, Visual mode: thing bounding boxes were not updated when changing things positions using Randomize mode.
Fixed, Visual mode: event lines were displayed at incorrect height when entering Visual mode for the first time.
Fixed, Texture Browser window: when MixTexturesFlats Game Configuration option is disabled, textures/flats are no longer shown in the Used group when flats/textures with the same names are used in the map. 
Fixed(?): probably fixed an exception some users reported when trying to initialize a Classic mode after switching from Visual mode with "Sync cameras" option enabled.
Changed, Game configurations, Thing Categories: a block must have at least one thing category property to be recognized as a thing category.
Changed, Visplane Explorer: the plugin now outputs more info when it fails to initialize vpo.dll.
Cosmetic, Thing Edit window, Doom/Hexen map format: adjusted UI layout so thing flags control no longer displays scrollbars in Hexen map format.
Internal: merged methods from UDMFTools into UniFields, removed UDMFTools. 
Updated Inno Setup script (added VC++ 2008 SP1 distributive). 
Updated ZDoom_DECORATE.cfg (A_CheckBlock).
Updated documentation (added "System Requirements" page).

Visual mode: fog distance calculation is now much closer to GZDoom one.
Visual mode: thing brightness calculation when a thing is affected by floor glow is now much closer to GZDoom one.
Linedef edit window, UDMF: added "Reset front/back brightness" buttons.
Sector edit window, UDMF: added "Reset ceiling/floor brightness" buttons.
Internal, Visual mode, Things mode: persistent event lines are now updated only when map objects are changed instead of doing it on every display redraw.
Internal: improved Dictionary lookup times when using map objects and textures as keys.
Internal: added "Release + Profiler" solution configuration.
Updated ZDoom_ACS.cfg (Warp).

Fixed, Visual mode: double-sided middle texture highlighting transparency check didn't take TEXTURES scaling into account.
Fixed, long texture names: textures located in a directory/pk3/pk7 root can't have long texture names.
Fixed, texture selector controls, long texture names: both long and short texture names should be added to texture name auto-completion list. 
Changed: "Grid Increase" and "Grid Decrease" actions can now be bound to mouse wheel.

Fixed, Visual mode: texture coordinate generated to test if double-sided middle texture is transparent was shifted 1 pixel up.
Fixed, Visual mode: offsets of GLDEFS lights were not affected by thing's angle.
Updated SharpCompress (0.10.3 -> 0.11.1).
Updated ZDoom_DECORATE.cfg.

Fixed, Visual mode, since r2336: in some cases local vertical texture offset was calculated incorrectly when checking sidedef's texture alpha.