Remove debugging flag.
Ensure guide sizes are non-negative.
Modify linear layout to crop stretching subviews before non-stretching subviews in the underflow case.
Rework the spacing adjustments.
Fix some edge cases around layouts properly handling sizeThatFits:CGSizeZero.
Fix some edge cases around layouts properly handling sizeThatFits:CGSizeZero.
Add spacingStretches property to layout.
Apply spacingStretches property to flow layout.

* Fix a bug in the code generation script.
Remove "default" layouts and the "noon" layout.