Fix for System.open_url

The following lines of code need to be added to support iPad 2. Without these lines, iPad 2 crashes on iOS 6 when trying to open the list of available apps to open the file with. This is to support opening files in other apps if file preview cannot read it.
iOS: support UIApplicationExitsOnSuspend
Merge pull request #115 from nhinze/patch-4

Fix for System.open_url
Merge branch 'master' of github.com:rhomobile/rhodes into neworm_xml_refactor
Additional XML description cleanup