This untangles some of the gigantic kitchen sink headers
in an attempt to split things into smaller files.
Also don't include gl.h, glext.h, windows.h,
and other such nonsense *everywhere*.
Lots of cleanups on the way too. More dead/unused code removal.
Remove incrFlag(), decrFlag() Lua functions.
This allows attaching multiple shader programs, processing the entire
screen as texture. Chaining shaders works, each shader will use
the output of the previous shader as input.
- Removed some unused member variables.
- The BBGE_BUILD_WIDESCREEN define is now gone.
- Added an TiXMLDocument cache to prevent parsing the same file
once for each entity on the map with the same skeletal.
- Removed Lua func entity_warpToPathStart, which was essentially a no-op
because Entity::followingPath was always NULL. Removed related code.
- Set texture wrap only when required.
(Some changes taken from https://bitbucket.org/mattbierner/ios-aquaria,
special thanks for changeset 72d6460d9e60)