Changed Control.setParent() to take the same argument type on all platforms; this is needed for re-adding Stack and Grid. This argument type is defined by each platform.
Re-added Stack. Of course it only works right on GTK+ right now... the other platforms's Control.preferredSize()s aren't implemented yet!
Renamed the controls* and containers* files to basicctrls* and containerctrls*, respectively, in preparation for the widget hierarchy redo.
Set up a new, cleaner model for deriving Control's methods and applied it to the Windows backend.
Applied the new Control system to the GTK+ backend.
Ported the new Control setup to Mac OS X.
Moved the definition of Control itself to control.go and updated some comments.
Moved the Mac OS X function newScrollView() to control_darwin.m and verified its styles against Interface Builder.
Fixed up attributes of Table on Mac OS X.