Merge pull request #84 from attilaz/master

iOS related improvements
Merge.
GL: Added check for texture formats.
Fixed compiler warning.
Fixed GL texture sampler state. Issue#85
Fixed NaCl crash.
Removed texture format check from Emscripten build (causes JS to stop responding).
Updated browser drawstress stats with Chrome 34 and Firefox 28.
Updated drawstress stats for browsers on Windows.
Added ability to set start vertex when setting vertex buffer.
Updated README.
Fixed texture formats for iOS.
Removed unused uniform.
Cleanup.
Added ability to retrieve uniforms used by shader.
Cleanup.
Cleanup.
Fix runtime check error on VS2013 in freetype
Use NULL as instance when loading predefined icon/cursor
Merge pull request #87 from sgraham/uninit-var-freetype

Fix runtime check error on VS2013 in freetype