Make the shutdown-helper GNOME Shell extension translatable.
Remove the Lock Screen button from the shutdown-helper. (Closes #8316)

After all, we may not want to support screen locking at all. And if we
do, the name of the "administration password" Tails Greeter option,
which then becomes overloaded with the screen locking ability, may not
be a good name.
Merge remote-tracking branch 'origin/feature/jessie' into feature/jessie
Prevent NetworkManager from starting at boot time (Closes: #8313).

We start it ourselves after changing the MAC address.