Common	(superclass: Composite) Common superclass for many other
	widgets. Defines some resources, types, converters, etc. and
	implements keyboard traversal.

History
1.1	Fixed keyboard traversal. Errors included:
	- widgets sometimes refused to release focus
	- in some cases programs crashed when iconified
	Visibility and unmap actions removed (they were not needed);
	highlighting is now only done when the focus is set
	explicitly; improved conditions in focusIn and focusOut.
