Map Analysis mode: fixed a couple of minor glitches related to enabling/disabling results list, "fix" buttons and "fix all" checkbox.

Updated documentation.

Map Analysis mode: results list now has a context menu, which allows to hide/show results based on type of selected result and to  copy description of selected result to clipboard.

Map Analysis mode: export to file command will now show "Save File" dialog instead of putting the file in the same folder as the map, also added some boilerplate.
Tag Explorer plugin: save to file command will now show "Save File" dialog instead of putting the file in the same folder as the map, also added some boilerplate.
Internal: reformatted GZCrash.log a bit.

Internal: more info is now displayed when a shader fails to compile.

Comments Panel: probably fixed a possible crash when UpdateList() is triggered during map unloading.

Map Options Form: example map name now uses current game's naming scheme.

Internal: optimized WAD.FindLump() and WAD.FindLumpIndex() functions. They should work ~30x faster now (although, overall performance increase because of this change is fairly noticeable).

View projection is now updated when engaging Visual mode. This means no more distorted visuals after disproportionately changing window size.

Game Configurations Form: added a help item to "Testing" tab, which displays info about command line placeholders when mouseovered.
Added some missing flags to ZDoom_DECORATE.cfg.

Linedef Edit Form, UDMF: a waring is now shown when trying to apply a non-zero action without any activation flags.
Program Configuration: selected test engine index was not saved when applying the form.
Program Configuration: selected test engine index was not pasted when pasting a game configuration or test engines.
Program Configuration: in some cases current test engine name was not saved when applying the form.
Program Configuration: fixed broken logic when trying to add a test engine with the same file name as already existing one.

Texture Browser Form: some minor logic fixes (no texture groups were selected when initial texture was empty and no texture group was stored in the program configuration).
Texture Browser Form: don't save current texture group when the form was canceled.
Keyboard Shortcut Reference export: generated html will now be saved to program configuration folder if working folder is write-protected.
Internal: added SupportedMapFormats property to EditModeAttribute. A mode with this property specified will be available only in specified map formats.
Interface: Ceiling Align Mode and Floor Align Mode are now enabled by default.
Interface: Ceiling Align Mode and Floor Align Mode are now only available in UDMF map format.
Interface: Visplane Explorer Mode is now available only in Doom map format.

Find & Replace Mode: sector effects and linedef actions are now searched on bit by bit basis. That means map elements with partially matching Generalized effect/action can now be found.

Internal, Edit Sectors form: more changes to "Slopes" tab logic. It's still incomplete...

Screenshots: message about missing save folder should not be displayed when using the default save path.
Screenshots: added wad and map names to info text of edit area screenshots.

Thing Edit form: absolute thing height was calculated incorrectly in some cases.
General: added a generic update logic when current editing mode doesn't handle OnEditFormValuesChanged event.
Internal, AngleControl: added "AngleOffset" property.

Updated documentation a bit.

Import .obj as Terrain: created terrain was horizontally flipped when importing a model with up axis set to X or Z.
Also, I would like to use this opportunity to thank Siberian Tiger from DTD Team for helping me with SVN builds for more than two years. You made my constant wrestling with the code a much less tedious process.

Import .obj as Terrain: vertex order was incorrect when creating sectors from a model with up axis set to Z.

Classic modes: Draw Grid, Rectangle and Ellipse modes were missing "toggle grid snapping" mode (enabled by holding Shift key while drawing).

Game Configurations: changed default map name for Doom maps to "E1M1".
New Map Form: "E1M1" is now used as a default name for Doom maps.
Thing Browser Control: double-click event is now sent only if user clicked in the node's label area.
Interface: added info messages for several toolbar toggles.
Interface: made Brightness icon more readable when using dark windows themes.

Visual mode, UDMF: added some boilerplate to prevent invalid sector slopes from showing up/crashing the editor. 

Fixed: MapSet.GetSectorByCoordinates() returned "false" in some cases when a given coordinate was on top of sector's vertex.
Internal: UDMF sector slopes and offsets are no longer stored in sector.Fields. Use sector.FloorSlope, sector.FloorSlopeOffset, sector.CeilingSlope and sector.CeilingSlopeOffset.

Visual mode, 3d floors: fixed broken 3d floor visibility detection (which failed in some cases when real floor or ceiling was sloped).

Tag Range plugin: tags can be set in relative mode (when this mode is enabled, generated values are added to existing tags instead of replacing them).
Updated documentation.

Map Analysis form is now resize-able.
Map Analysis form: number of found errors is now shown in the form's title.

Game Configurations, Error Checker: all blocking things are now checked for being stuck in other things.
Thing Type Info: errorcheck is now set to THING_ERROR_INSIDE_STUCK for blocking DECORATE things.

Tag Selector: tags can now be set relatively using "++N" and "--N" syntax.

ACC: Also updated zdefs.acs and zspecial.acs

Added custom icons for ZDoom's Decal and Sparkle things.