G.Layer

Implemented rawer Layer class, containing addToStage method. The Gesso
main class will use this to implement the globals.gesso
expand settings uses getterSetter

a points reference is copied to the object and spy'd by get set of all
Point attributes. The result ensures location data is propagated to the
point object regardless of reference object.
smarter defaulting logic

Bug in line data:
+ receives stroke width of other elements
+ object mapping of x2 and y2 not functioning