On: Nuklear: A small ANSI C GUI toolkit

[fdb]

I've got it running on OS X with some modifications:

- In the Makefile, use

  LIBS = -lglfw3 -framework OpenGL -lm -lGLEW

- In the main.c file of the project, change headers to use <OpenGL/gl.h> and <OpenGL/glu.h>

- In the shader code, change "#version 300 es" to "#version 400" for both the vertex and fragment shader.

I'll try to make a PR with conditionals if I can find the time today.