Script binding updates.
Change "bool" to "Boolean".
Updated the PopulateTextLines method so that it accepts the Line Width to be used when populating lines, rather then getting it from preset variables on the text layer.
Fixed a compile error with interpolator seriailzation.  MEZZ_LIB is not necessary on methods that are implemented in the header.
Added a new sizing policy capability.  Now widgets can be vertically sized based on the room needed to display their text.  This is the default sizing for ListBox items now.
Fixed a few bugs in the UI system shutdown sequence that were causing seg faults.