Region Constraint moved to become a member and introduced getters and setters
Constraint mechanism has change to be based on abstract individual constraints.
Removed IsEmpty() from RatioConstraints
Commenting
gxASSERT changed to gxAssert
Step 1 in migrating constraints into an object based dynamic map.
Attempt to streamline constraint into a base class template
Change gxRegionConstraint from a class to a typedef
gxRegion is now a class, with its constraints defined in it

This allows a general get method.
Reverted constraint getters to old system of getRegion instead of get<gxRegion>
Commented (removed) Rect from Constraints
Flex is now added as dynamic constarint
Constraint ID changed to enum
Constraints Are now fully implemented using dynamic maps.