Refactored IE detection, add support for a specific version

git-svn-id: http://primefaces.googlecode.com/svn/primefaces/trunk@11775 5a70e874-a5cb-11dd-8af2-493fb0bb9f7c
Refactor

git-svn-id: http://primefaces.googlecode.com/svn/primefaces/trunk@11776 5a70e874-a5cb-11dd-8af2-493fb0bb9f7c
Force png barcodes in IE 8 and older.

git-svn-id: http://primefaces.googlecode.com/svn/primefaces/trunk@11777 5a70e874-a5cb-11dd-8af2-493fb0bb9f7c