Local coordinate space support + new Apple Homepage Transition example

• Support local coordinate space.

  Global coordinate space	Local (parent's) coordinate space
  Animating views are not affected by parent views' attributes	Animating views are affected by parent views' attributes
  When parent view moves, subviews that have its own modifiers do not move with the parent view. I.e. they are being taken out of the view hierarchy.	When parent view moves, subviews that have its own modifiers move along with the parent view. I.e. similar to how a view behave when its parent view moves.
  Used for matched views & views with source modifier. Global is the default prior to 0.1.3	Local is the default coordinate space after 0.1.3

• New useGlobalCoordinateSpace modifier. Force the view to use global coordinate space. I.e. won't move with its parent view.