Add Ruby Gem instruction

Didn't know whether to grab 'MotionKit', 'motionkit', or 'motion-kit'. This clarifies.
Merge pull request #13 from ryngonzalez/patch-1

Add Ruby Gem instruction
VERY easy fix (too easy?) for the improper %-size from #10
check numberOfLines
README updates
notes about custom root view
examples
remove unnecessary 'fetch'-es
adds specs to style the UIButton#titleLabel
just makin sure it wasn't passing because values were the default values
Renamed ViewLayout to TreeLayout which better describes what it does
Merge pull request #17 from rubymotion/refactor/rename_view_layout_to_tree_layout

Renamed ViewLayout to TreeLayout which better describes what it does
better 'NoMethodError' messages
Fix option A: use 'MotionKit.color_class', which returns a platform-specific class, and has shared code
even though this method usually doesn't get a block, wrappers (e.g. wrapping the 'on' method so that sugarcube's 'on' helper works) might need to send a block
updated documentation, and by moving 'block' out of create, we get one less method in a potentially *long* stack trace
version bump, 0.9.6.  fixes CAGradientLayerLayout and other misc.
don't need 'new' here
suppress warning message
update Gemfile and lock files