Moved to floating point color via NVGcolor structure.
Currently working with gl3buf backend.
Converted gl2 path.
Converted gl3 unbuffered version.
Warning/Error fix: added int return type to nvgIsBlack
Converted spaces to tabs.
Added nvgRGBf and nvgRGBAf constructor functions.
Added nvgTransRGBAf
Removed nvgIsBlack, and added isBlack to demo.c
Bugfix to nvgRGBf
Merge pull request #56 from dougbinks/NVGcolor

Merged NVGcolor, which implements the color as floats, colors can be > 1.0, allowing HDR rendering when needed.