added new graph style
Fix texture completeness for non-POT textures on GLES2/WebGL
Fix for issue #155

- added NVG_DEBUG which can be used to omit calls to glGetError()
- removed return value for glnvg__checkError
- create flag defines to enum
Moved image repeat (tiling) from pattern to image creation

- API changed!
- moved image repeat from nvgImagePattern() into image creation
nvgCreateImage*()
- made flip-y and premultiplied common image flags (not just GL)
- removed nvglImageFlags(), flags passed in via
nvglCreateImageFromHandle() flags
- nvgluCreateFramebuffer takes image flags as param
Fixed tabs vs spaces

Removed old shader uniform code

Cleaned up uniform array code