Removed debugging code.
Fixed a bug to reflect a bad shader better.

This then does not require the user to check the
zen::gfx::zLight::Init() call's return value, and will just cause an
assertion to fail later (in ZEN_DEBUG_BUILDs), because the program
object will not exist.
Minor restructuring.
#4: Fixed double-light initialization in levels.
Re-enabled ambient lighting shader.
#4: Fixes attribute saving bug.
#4: Merges local changes with latest master.
Improves cross-platform timing implementation.
Conforms socket type to be unsigned.
Fixes memory leaks with polygon inheritance.