Fixed EntryElements to use a separate key for password entries
Fixed EntryElements to use a separate key for password entries

Fixes http://stackoverflow.com/questions/13706729/why-are-some-of-these-monotouch-dialog-cells-appearing-empty

Milan1992/MonoTouch.Dialog,hisystems/MonoTouch.Dialog,jstedfast/MonoTouch.Dialog,newky2k/MonoTouch.Dialog,benoitjadinon/MonoTouch.Dialog,danmiser/MonoTouch.Dialog,ClusterReplyBUS/MonoTouch.Dialog,migueldeicaza/MonoTouch.Dialog