Fix for issue #718; fixes problems that would occur when adding/inserting a child Widget into its own parent HorizontalPanel or VerticalPanel. Found by: fredsa Patch by: bobv Review by: scottb, jgw git-svn-id: https://google-web-toolkit.googlecode.com/svn/trunk@1008 8db76d5a-ed1c-0410-87a9-c151d255dfc7