- added documentation about changed GL state
- made old GL2 and GL3 backends obsolete

- added support for GL(ES)2 for nanovg_gl3buf (something is still not
quite there)
- nanovg now sets all required GL state
- removed compiler warnings about unused vars

- changed tessellation threshold from 0.3 to 0.25
- fixed scissor AA on retina
- fixed stroke AA on retina

- added support to take screen shots
- added support to render to frame buffer using premultiplied alpha
- fixed spelling NVGaling -> NVGalign

- removed assize from the back-end api
- moved image to paint in renderTriangles call

- added NVG_NOTUSED to suppress unused param warnings
- fixed scissor anti-aliased border width when zoomed

- fixed off-by-one pixels from demo
- added device-pixel-ratio support (retina support)
- added nvgEndFrame()

- use nvgCreateGLES2() instead of nvgCreateGL2() when NANOVG_GLES2 is
specified (ditto for gl3)
- use GL_RED instead of GL_LUMINANCE in ES3

- added option to turn off AA fringe generation
- added examples which use no AA fringes and  MSAA

- merged GL ES2 and GL2 backends
- GL2 uses now same structure as GL3

- set swap interval to 0 to better see performance
- draw convex shapes without stencil to speed things up
- improve vertex buffer upload for gl3

- moved demo stuff to separate file
- created two separate examples for gl2 and gl3
- initial stab at OGL 3.2 core profile back-end (currently twice as
slows as 2.0)
- API change: glBeginFrame() takes view witdth and height as input
- added FPS counter to demo

- updated font stash
- added end parameter to text (can draw substring)
- text and text measure return advance/width