Fixed P2P UI integration realted logic
- Check to see if manifestURL is registered or not before showing P2P UI
- renamed the DOM API to 'validateManifestUrl'
- Added couple more IPC messages between child and parent process
Merge branch 'master' of ssh://github.com/svic/mozilla-central into hashPeer01

Conflicts:
	dom/system/gonk/Nfc.js