Fixed stack widget after jquery upgrade

git-svn-id: http://primefaces.googlecode.com/svn/primefaces/trunk@9593 5a70e874-a5cb-11dd-8af2-493fb0bb9f7c
Use prop instead of attr.

git-svn-id: http://primefaces.googlecode.com/svn/primefaces/trunk@9595 5a70e874-a5cb-11dd-8af2-493fb0bb9f7c
Use prop instead of attr.

git-svn-id: http://primefaces.googlecode.com/svn/primefaces/trunk@9596 5a70e874-a5cb-11dd-8af2-493fb0bb9f7c