Integrate SMTP
Add support for kde polkit, closes #2630

Close issue #2630
Add changes file for #2630
Add documentation to '_is_auth_agent_running' method.
Add command to run the client in hacking section

Also document the --danger flag for the client run
Merge remote-tracking branch 'ivan/bug/doc-command-to-run-client' into develop
Merge remote-tracking branch 'ivan/bug/kde-polkit-support' into develop
Handle 'Incorrect Password' exception.

closes issue #2640.
don not automatic login if there is no password
add changes file
Merge remote-tracking branch 'ivan/bug/keyring-crash-on-wrong-password' into develop
fix restore from minimized. Closes #2574
add script for installing virtualenv
Merge remote-tracking branch 'kali/feature/ci-bbot-setup' into develop
Add oxygen icons
Move KeyManager submodule from leap.common to here.
Add logging handler with history and signal emision
Add logger window connected with the leap_handler
Integrate LoggerWindow with client
Merge remote-tracking branch 'ivan/feature/logger_window_rev4' into develop
adapt test suite to latest client code

* fix run_tests
* add tox.ini
* cleanup/update requirements
* fix coverage reports
* add pypi badge
make tests pass & fix pep8
Merge remote-tracking branch 'kali/feature/ci-ready' into develop
Add dependency on python-gnupg.