Closes: #4035

This falls in the "quick" workaround category.

A proper state machine that extends the four basic connection states
is hence needed. We have to accomodate design to have a
connection-oriented state machine in the backend (I would favor a
twisted protocol for this), and a more lightweight one that conducts
the gui-level changes (ie, change the actions / buttons / labels
accordingly).

Since this "cancel" functionality has been long postponed, I chose
to do one more ugly hack here, that is, show and hide dance with a
button that just calls the bitmask-root to kill the vpn process. It
should work well enough until we get to the reorganization needed for a
clean process control for eip.

This way we get rid of Qt on the backend side.
The use of QSettings in the backend was breaking the app on OSX.

Remove global variable in favor of a helper method that returns the
country code.
Needed in order to split backend/frontend.