Hide AKM menu and disable the qt connection.

Hide the Advaneced Key Management menu from the ui file and comment out
the connection between the triggered action and the method that shows
the AKM window.

Closes #6087.
Merge remote-tracking branch 'refs/remotes/ivan/feature/6087_remove-AKM-menu' into develop
Use wheels! yeah!

No more infinite time to re-create a virtualenv.
Merge branch 'kali/use-wheels' into develop
bump version

because we've updated it with mail fw.
Merge branch 'kali/bug/bump-bm-root-version' into develop
single pref win: move eip preferences to new combined preference window.
single pref win: enabled/disable services via preferences window, account page.
single pref win: moved password change UI to a separate window, opened from account page in preferences.
single pref win: gets the autopep8 beauty scrub.
single pref win: clean up vpn pref error displaying & don't show dummy gateways in case of error.
single pref win: move preference window tracking to PreferencesWindow
single pref win: minor linting & add changes file
single pref win: added shortcut to preferences
single pref win: ensure proper deletion of preference window pages.
single pref win: fix problems with cleaning up closed windows (lambdas were keeping the python object from getting garbage collected, and this keeps the old signal connections active)
country flags: add default fallback xx.png flag.
Use python2.7 instead of python2.

The binary `python2` is not present on Debian systems.
The common denominator for Ubuntu, Debian, Arch is `python2.7`

Related to #6048.
Merge remote-tracking branch 'refs/remotes/ivan/bug/python2-compat' into develop
Merge remote-tracking branch 'elijah/feature/prefui' into develop