added strigns values for broadcast and to build the IncomingDrinEvent
added copyright notice, permissions, filters for BroadcastReceiver and DrinIncomingCallReceiver
implemented sendDrinEvent method and fixed javadoc comments
fixed custom broadcast actions and commented code
added onDestroy method, fixed onServiceDisconnected, onServiceConnected and doDiscover
receives PHONE_STATE action, builds and fires IncomingDrinEvent on CALL_STATE_RINGING