methods of the controller looking for a handle<foo> method where <foo> is
the action command. The arguments to the method are allowed to be either
none, the source object that generated the action or the source object and
the action argument (which requires that the action be a CommandEvent).
git-svn-id: https://samskivert.googlecode.com/svn/trunk@680 6335cc39-0255-0410-8fd6-9bcaacd3b74c