initial adoption of closures in the math library.  all unit tests pass.
fix three missed conversions to closures.  switch to extending math prototypes rather than replacing them.  This is to ensure that types created in closures within a type's prototype definition get their prototype updated with the full definition.
add source for THREE.extend method.
Merge remote-tracking branch 'bhouston/math-closures' into dev
Removed re-asigning of constructors.
r56dev
Updated builds.