Add support for fingerprint-gui's polkit agent.

Closes #5880.
defer encryption
wait for decrypt during bootstrap
Merge remote-tracking branch 'refs/remotes/ivan/feature/add-fingerprint-gui-polkit-support' into develop
firewall stop: try to be much more robust in stopping the firewall whenever we can
Use preferred provider on first run. Closes #5813.
Code style fixes.
Add changes file for #5813.
Merge remote-tracking branch 'refs/remotes/ivan/feature/5813_wizard-providers-order' into develop
Add packaging for osx with py2app
Add bitmask.icns file
Merge remote-tracking branch 'chiiph/feature/package_osx_py2app' into develop
bitmask-root: rip out all resolvconf code and simply rewrite all DNS packets to use the VPN nameserver.
bitmask-root: pep8'ed
Use better message for the initial sync.

Closes #5875.
Merge remote-tracking branch 'refs/remotes/elijah/feature/routedns' into develop
invoke mainwindow.quit only from parent pid
because the fork happens after the registration of the signal handler,
all children processes were inheriting the handler (and being passed a
reference to the mainwindow object, ugh...)
call soledad close
Merge remote-tracking branch 'refs/remotes/kali/feature/syncdb-adapt-3' into develop
Merge remote-tracking branch 'refs/remotes/ivan/bug/5875_better-initial-sync-message' into develop