Relax stroke width limit
Merge upstream/master
Use highp precision when available for GLES
Merge pull request #102 from notlion/gles-highp

Use highp precision when available for GLES
Separated fill and store expansion code
Merge pull request #93 from jacereda/master

Relax stroke width limit
Merge pull request #101 from starwing/master

add external APIs to GL backend to get native Texture Id.
Fixes and tweaks for frame buffer handling

- fixed flags setup in nvglCreateImageFromHandle
- changed frame buffer to only compile on GL3
- changed nvgluCreateFramebuffer() to return FBO struct instead of
filling existing one (for consistency)
Fix for issue #100

- fixed glyph position bounds for whitespace
Fix for issue #95

- Added alpha for images
- Added global alpha
Made FBO helper to work on OSX when using GL2
Fix for issue #92

- added (optional) 3-pass stencil trick to stroke rendering, reduces
overdraw artifacts, a little slower
- fixed some text bounds issues
fix nvgCreateImageFromHandle for GLES2/3.