Added nme.gl.GLUtils

GLUtils is currently just utility methods for creating and linking
shaders and programs, and creating 2D and 3D perspective projection
matrices
Added a few utils

StopWatch is a convenience class for getting a scaled delta value based
on repeat calls to tick()
Keymanager is a convenience class for tracking pollable key states
through a map
StringUtils should be where any and all generic convenience methods go
for String manipulation. Currently it just offers a capitalizing
function.