* Remove references to esoteric EXT_abgr and EXT_bgra extensions entirely, which might even be causing issues on some systems, instead replaced with standard OpenGL 1.2 constants
 * ARGB8 and BGRA8 formats now support sRGB -> linear conversion if sRGB pipeline is used, previously they were ignored.
 * All float and half float formats are considered supported if we either support OpenGL 3 or ARB float texture.
 * Cleanup TextureUtil a bit by removing constant references from ARBHalfFloatPixel, ARBTextureFloat, EXTPackedFloat, EXTTextureSharedExponent and EXTTextureSRGB to GL21 and GL30 classes (which are identical anyway).
 * Check if we support sRGB textures before choosing sRGB format (although this check should have been done earlier? not sure..)
Merge branch 'master' of github.com:jMonkeyEngine/jmonkeyengine