Refactoring of OpenGL backend; oh so much tidying

[GoogleCodeExporter]

Purpose of code changes on this branch:
To reduce code duplication between the OpenGL-based backends (WebGL, Android 
and future OpenGL-based backends).

To substantially simplify the Android graphics backend.

When reviewing my code changes, please focus on:
https://github.com/threerings/playn/commits/opengl-revamp

You can see the whole change as diffs here:
https://github.com/threerings/playn/compare/aca6c8572f015c4968a6838f41cd63f99617
db66...b54a946045e753943b280ab59c41e7124ac0d25f

After the review, I'll merge this branch into:
/trunk

Original issue reported on code.google.com by samskiv...@gmail.com on 11 Jan 2012 at 8:21

[GoogleCodeExporter]

Added a few more niggling fixes.

https://github.com/threerings/playn/compare/aca6c8572f015c4968a6838f41cd63f99617
db66...c027b5885941f137609eb19a5d266b3837013ed9

Original comment by samskiv...@gmail.com on 11 Jan 2012 at 8:40

[GoogleCodeExporter]

I responded on the email thread to say "I haven't reviewed every detail, but 
this looks good enough to me to move forward. Let's commit it and address 
problems as they arise".

Original comment by jgw@google.com on 13 Jan 2012 at 9:30

• Changed state: Accepted

[GoogleCodeExporter]

Shipped.

Original comment by samskiv...@gmail.com on 13 Jan 2012 at 10:09

• Changed state: Done