- Improved D24S8 color format handling in OpenGL.
- Fixed issue with wrong size for OpenGL RT when FBO isn't available. Thx CuteAlien for report that.

git-svn-id: svn://svn.code.sf.net/p/irrlicht/code/trunk@5222 dfc29bdd-3216-0410-991c-e03cc46cb475