Fix to mobile overlay pannel bug toggle

Fix to mobile overlay pannel bug toggle, https://code.google.com/p/primefaces/issues/detail?id=6874
This is a pending bug in 5.0 final release. Since primefaces team busy and no time to fix/review community issues.

Policy discussion
http://forum.primefaces.org/viewtopic.php?f=3&t=38256
Defect discussion
http://forum.primefaces.org/viewtopic.php?f=8&t=36784