Fixed dynamic columns sorting problem

git-svn-id: http://primefaces.googlecode.com/svn/primefaces/trunk@11847 5a70e874-a5cb-11dd-8af2-493fb0bb9f7c
Dropped support for static sortBy values in multisort.

git-svn-id: http://primefaces.googlecode.com/svn/primefaces/trunk@11848 5a70e874-a5cb-11dd-8af2-493fb0bb9f7c
bugfix

git-svn-id: http://primefaces.googlecode.com/svn/primefaces/trunk@11850 5a70e874-a5cb-11dd-8af2-493fb0bb9f7c