- Progressive undo/redo system (much faster and up to 1000 undo/redo levels) Please note that several plugin functions and properties have changed.
- Some small optimizations in the classic 2D rendering (cached linedef flags, reduced some unneeded redrawing)

@ Changed the MapSet to work with arrays instead of linkedlists. Because the index is now know for each element and can be retrieved in O(1) efficiency it has become a property (Index) for all map elements. GetIndexFor* functions have been removed. Get*ByIndex are now also of O(1) efficiency.

Replacing can now be made undone

Added variable "skyflatname" as a game configuration item. It is used to ignore false positives when checking for missing textures. Updated all the game config files to make use of this feature.

- Added HighlightedObject property to the EditMode class, the object returned depends on the editing mode and the current highlight
- Exposed several properties in the ClassicMode class

Fixed updating used textures when pasting so that they are loaded and displayed on the geometry surface

- Little optimization in MarkSelected... functions

- Some minor interface polishing

- Fixed potential crash and "ghost thing" left-over after cancelling pasted things

Removed option "keep selection" from Find & Replace dialog (not sure why I put that there, it doesn't do anything)

Fixed a bug with sector highlighting in Visual Mode (occurred when a sector contains lines that have the same sector on both sides)

@ removed unneeded dxwebsetup from the setup installer (directx redist is already included in the slimdx package)
- Added options to move both floor and ceiling together when a sector height change action is used on walls.

- Fixed highlight and selection in visual mode when shader model 2.0 is not available
- Added option to turn off glow animation of highlight and selection in visual mode

- Pixel Shader model 2.0 is now always used when available (regardless of High Quality Display option)
- Edit Selection mode now updates surface geometry when drag is released

- Some visual aesthetics
@ Fixed the "Release with revision lookup" config output directories

Added source code for Map Statistics plugin. Most simple plugin ever, see this source code to learn the very basics of making a Doom Builder 2 plugin. Lot of comments in the source code to explain why things are needed.