Keyboard accessibility support for menubar

git-svn-id: http://primefaces.googlecode.com/svn/primefaces/trunk@9933 5a70e874-a5cb-11dd-8af2-493fb0bb9f7c
Non-circular navigation

git-svn-id: http://primefaces.googlecode.com/svn/primefaces/trunk@9934 5a70e874-a5cb-11dd-8af2-493fb0bb9f7c
Refactor

git-svn-id: http://primefaces.googlecode.com/svn/primefaces/trunk@9935 5a70e874-a5cb-11dd-8af2-493fb0bb9f7c
Bug fix

git-svn-id: http://primefaces.googlecode.com/svn/primefaces/trunk@9936 5a70e874-a5cb-11dd-8af2-493fb0bb9f7c