@ Made CreateTexture and ReleaseTexture public: Plugins must be allowed to load images as textures in video memory.

@ added calls to FindDefaultDrawSettings() when opening / creating a map to ensure these defaults exist

@ Fixed an undo/redo bug that caused problems in Visual Mode when multiple levels are undone at once

ZDoom (Doom in Doom format) and ZDoom (Doom in Hexen format) game configurations now makes use of included configurations

@ Missing include paths are now reported as errors

Heretic game configuration now makes use of included configurations

@ Removed unique key check in configurations: Setting with the same name now just overrides the previous.

Exposed MapOptions for plugins and added funtions to read and write settings in the map options (dbs file)

- Doom configuration now makes use of included configurations

Restructured configuration parsing code and added a file include system. Use in structure where to include a file like this:  include(file [, structurepath] );

Fixed a bug in the thing/linedef argument input boxes that caused an incorrect value when only increased/decreased with the up/down buttons