Fix Issue #212: Added DOM methods to support the creation of the <CAPTION>, <COLGROUP>, <THEAD>, and <TFOOT> elements.
Patch by: sandymac, me
Reviewed by: jgw

git-svn-id: https://google-web-toolkit.googlecode.com/svn/trunk@537 8db76d5a-ed1c-0410-87a9-c151d255dfc7