Merge pull request #75 from dariomanesku/master

18-ibl example and some minor fixes.
Updated README.
Added precision specifier defines for embedded shaders.
Added 18-ibl screenshot.
Fixed EXT_bgra handling.
Updated README.
Fixed: Swizzle works only for BGRA8.
Added EXT_shader_texture_lod support.
Added dynamic loading of EGL library on Windows.
Updated log message with renderer name.
GL import code cleanup. Added ability to load GLES library dynamically.
GL import fixed for OSX and iOS.
GL import fixes for Linux.
Fixed GLES3 build.
Fixed TextureFormat::Enum order for PVR1xA textures.
Added ability to skip top level mips when parsing texture format.
Fixed createTexture default argument error.
Added ANGLE extensions.
Fixed 08-update example.
Cleanup.