Turns scale into a first-class layout function, correctly impacting frame and clippingFrame.
- Adds SC.scaleRect, a convenience method for scaling a rectangle about an origin.
- Adds two new layout properties, transformOriginX and transformOriginY, to control the origin of scale and rotate properties.
- Frame and clippingFrame now take scale, transformOriginX and transformOriginY into account. As previously (but moreso now that scale is involved),  is relative to a view’s parent’s coordinate grid, while  is relative to a view’s own coordinate grid.
- Includes unit tests.
Overhauls SC.ScrollView#scale, and a number of related subsystems.
- Adds official SC.Scalable protocol.
- Overhauls SC.ScrollView#scale, decoupling it from touch events and allowing it to be bound and set. Updates it to use layout scale property when not mid-touch. Improves and isolates special mid-touch scroll & scale positioning.)
- Bonus: Fixes a visual glitch in the default Ace scrollers where the thumb would overlay the buttons by a couple pixels too many. Looks much cleaner now.
Includes unit tests.