A GL Hello World.

Demonstrates how to use Bro to bind the OpenGLES library well enough to compile
a shader program, upload some vertex data and draw it.

I'll eventually "enable" more of the GLES2 bindings, but I want to do that in a
context where they're getting tested.
New sample: Touches
https://developer.apple.com/Library/ios/samplecode/Touches/Introduction/Intro.html
Update samples with iOS 8 compatibility and layout constraints (where applicable)
Fixed headers.
Merge pull request #12 from samskivert/hello-gl

A GL Hello World.