Wipe pin and data hiding

Added functionality:
* Catching phone number `#666`
* Hiding data upon receiving `#666` phone number
* Toasts showing the state of the app:
    * Started without phone number
    * Showing data when dialing `#555`
    * Hiding data when dialing `#666`

**The app does not respond to a phone number correctly if it is active**. To fix this, we will either have to kill the app when exiting it (which seems wise, as we want it removed from the recent apps anyway), or fix the ContentManager so that it restarts every time the app is called. That, or the resolution of the phone numbers should be altered.

Ready for merge.

fixes #5.