Initiated work to make sortBy-filterBy fully compatible between 3.x and 4.x to support both approaches same time for backward compatibility.

git-svn-id: http://primefaces.googlecode.com/svn/primefaces/trunk@10204 5a70e874-a5cb-11dd-8af2-493fb0bb9f7c
Default sorting support for single sort.

git-svn-id: http://primefaces.googlecode.com/svn/primefaces/trunk@10205 5a70e874-a5cb-11dd-8af2-493fb0bb9f7c