Added Calendars.withCopy() at Jamie's request.
Added Calendars.withCopy() at Jamie's request.


git-svn-id: 64ebf368729f38804935acb7146e017e0f909c6b@2633 6335cc39-0255-0410-8fd6-9bcaacd3b74c

samskivert/samskivert,samskivert/samskivert