UI: refactoring

No major functional changes though this greatly improves /
tightens up internal classes and interfaces.

Most notibly config is no longer passed around everywhere,
if a component needs to access it it simply can call out
to Omega.Config.

Also the resource (mesh geometry / particle / etc) interface
and mechanisms have been significantly improved and should
now be lightweight / leaner.

Tests still need to be updated but this should serve as a
solid base for additional enhancements.