Game Configurations: added "Thing Radius" (23) and "Thing Height" (24) action argument types. When non-zero, arguments of these types will affect the size of associated thing in Classic and Visual modes.
Game Configurations: updated things in ZDoom "Bridges" category to use argument types 23 and 24.
Documentation: added "Action Argument Settings" page, updated "Basic Settings", "Map Format Settings", "Linedefs Settings" and "Things Settings" pages in Configurations -> Game Configurations group.
Documentation: updated "DECORATE keys" page.

Replaced Hourglass3D.png with the one, which matches the style of MissingTexture3D.png and UnknownTexture3D.png.

Sector Edit Form, UDMF: Sound Sequence selector is now a drop-down populated by values parsed from SNDSEQ.
Documentation: updated "(G)ZDoom text lumps support" page.
Updated udmf_zdoom.txt.

Fixed(?), PK3: SharpCompress doesn't like it when several threads try to read PK3 archive entries at the same time.
Fixed, Visual mode, 3d floors: floor and ceiling alpha calculation was broken.

Fixed several places where KeyNotFoundException can potentially occur in ThingFlagsCompare.Compare().

Updated ZDoom_ACS.cfg and ZDoom_DECORATE.cfg.

Fixed, Game Configurations window: current configuration was not marked as changed when changing nodebuilders or engine test parameters.
Fixed, Game Configurations window: current map is marked as changed when applying changes done in the window.
Changed, UDMF saving: removed extra line break between map elements.

Fixed, "Flip Linedefs" action: in some cases my sector based flipping logic was behaving incorrectly.

Fixed: we don't need to reload ResourceImages, because they can't be unloaded and reloading them can cause problems when trying to display them in PictureBoxes.
Removed Sector Brightness Mode keyboard binding from the default program configuration file.

Added: thing and linedef action arguments can now have tooltips defined in both Game Configuration (using "tooltip" action argument definition property) and DECORATE (using "$argNtooltip" special comment).
Removed "Sectors Brightness Mode" action, because the mode itself was removed long ago...
Documentation: updated "DECORATE keys", "Things Settings" and "Linedefs Settings" pages.

Fixed, MAPINFO parser: properties, written like '667=CuteCaco' were not parsed, while '667 = CuteCaco' worked fine.
Changed, Classic modes: increased maximum zoom level to 9000% (was 3000%).
Added, General interface: added "800%" zoom level to the bottom toolbar zoom menu.
Added, General interface: added "400%" and "800%" zoom levels to "View -> Zoom" menu.

Sectors mode, "Raise/Lower Sector Brightness" actions: we should display the actual increment instead of "8".
UDMF: changed the name of "midtex3dimpassible" flag.
Updated ZDoom_DECORATE.cfg.

Fixed, MAPINFO parser: the parser was unable to handle DoomEdNum block's action special definitions.
Fixed, DoomEdNum handling: in some cases ThingTypeInfo was not assigned a proper DoomEdNum and was not placed in a ThingCategory.

Fixed, .obj Terrain Importer mode: the mode was not canceled properly after failing to import a model.
Fixed, .obj Terrain Importer mode: the mode was unable to parse .obj vertex/face definitions generated by some (Cinema4D) modeling programs.
Changed, .obj Terrain Importer mode: vertical (e.g. perpendicular to up axis) polygons are now skipped during model importing.
Changed, Ceiling Align mode, Floor Align mode: changed rotation steps form 45 to 15 deg.

Updated ZDoom_DECORATE.cfg.

Game configurations, Strife, Doom map format: several thing flags were named incorrectly.
Game configurations, Strife, Doom map format: several linedef flags were listed as "Unknown".
Edit Selection mode: 15-degree rotation steps require more precision...

Fixed, Map Analysis mode, Check Stuck Things: in some cases the check returned false-negative results.

Changed, Visual mode, Auto-align textures actions, UDMF: aligned texture coordinates are no longer rounded to integer values.
Changed, Things, Sectors, Linedefs, Vertices modes: we shouldn't select highlighted map element during the copy action when no map elements are selected.
Internal: removed some debug stuff from CheckTextureAlignment and ResultTexturesMisaligned.

Edit Selection mode, UDMF: sector slope offsets are now updated to keep them at the same position when moving or rotating sectors.

Changed, Thing Edit Form: floor slopes are now taken into account when changing thing's absolute Z position (currently, only slopes, created using sector planes, vertex height offsets and "Plane_Align" (181) action are supported).
Changed, Thing Info panel: floor slopes are now taken into account when showing thing's Z position (same plane type limitations as above).
Changed, Thing Info panel: thing position is now shown as "X, Y, Z (abs. Z)".

Drag Geometry mode, UDMF: sector slope offsets are now updated to keep them at the same height when moving sectors.

Added GZDoom's glowing flats (http://www.zdoom.org/wiki/GLDEFS#Glowing_flats) support to Classic and Visual modes.
MAPINFO: added "DoomEdNum" and "SpawnNums" blocks support.
MAPINFO: added "#include" directive support.
MAPINFO: added "$gzdb_skip" special comment support.
DECORATE: "spawnthing" Game Configuration block is now updated using "SpawnID" actor property.
Game configurations: added "class" property to the most of ZDoom things.
Actions: removed "Reload MAPINFO" action.
Documentation: merged "GLDEFS and MODELDEF support", "(Z)MAPINFO support" and "TEXTURES support" topics into "(G)ZDoom text lumps support", added info about the other text lumps GZDB can use.

Updated InnoSetup config file. 

Changed, Thing, Linedef, Sector info panels: flags are now shown in the same order as in corresponding Edit forms.
Changed, Linedef info panel: activation flags are now displayed before "regular" flags and using different color.
Added, Linedef info panel: sidedef flags are now displayed.

Fixed, internal: in some cases it was possible to get incorrect resource when using Plug.GetResourceStream().

Fixed, Sectors/Linedefs/Vertices modes: 3D floor color indicators should be updated after deleting a map element.
Documentation: added "List of deprecated plugins" topic, slightly changed topics layout.

Fixed, Open Map Options window: when everything else fails, we should also check game configurations without resources.
Documentation: fixed a couple of typos.

Game configurations, Hexen things: added "Spawn Fly" (112) actor definition.

Linedefs mode, Help panel: replaced info about "Flip Sidedef" action with info about "Flip Linedef" action.
Find and Replace Mode: renamed "Linedef Actions" search mode to "Linedef Action and Arguments".
Find and Replace Mode: renamed "Thing Action" search mode to "Thing Action and Arguments".
Cosmetic layout changes in Find and Replace window.
Updated documentation.

Changes in "Linedef Action and Arguments" and "Thing Action and Arguments" search modes:
Changed arguments search syntax from "action;arg0,arg1,arg2,arg3,arg4" to "action arg0 arg1 arg2 arg3 arg4"
You can now find ACS script actions with named scripts using "action arg0str ..." syntax.
You can now replace arguments using the same syntax as in the "Find what" field.