Updates, extensions and comments for Vector2,Color,Point and Rectangle

Changes :

Vector2 :
	-now fully commented,
	-all things sorted within the regions,
	-added ToPoint method,
	-added missed overloads from XNA, for Transform and TransformNormal

Color:
	-some comments changed,
	-all things sorted within the regions,
	-added Invert static method,
	-increase performance for == and != operators,
	-some cleanup	

Point:
	-some comments changed,
	-increase performance for all operators

Rectangle:
	-few comments changed,
	-ToVector4 added