Added support for locking the IOS device for a number of seconds.

Removed unused code
Merge pull request #795 from mutualmobile/ios_lock

Added support for locking the IOS device for a number of seconds.
Added support for backgrounding the IOS application for a # of secs
Merge pull request #794 from mutualmobile/ios_background

Added support for backgrounding the IOS application for a # of secs