SplitButton fixes required after new menumodel implementation.

git-svn-id: http://primefaces.googlecode.com/svn/primefaces/trunk@8999 5a70e874-a5cb-11dd-8af2-493fb0bb9f7c
Refactor

git-svn-id: http://primefaces.googlecode.com/svn/primefaces/trunk@9000 5a70e874-a5cb-11dd-8af2-493fb0bb9f7c