Fixes issue #1002; the text and icon of a stackpanel frame would not trigger an expansion.  This was an unintended side effect of handling nested stackpanels correctly.

Found by: martin.portmann
Review by: knorton

git-svn-id: https://google-web-toolkit.googlecode.com/svn/trunk@1028 8db76d5a-ed1c-0410-87a9-c151d255dfc7