Add support for Mate's polkit agent.
Merge remote-tracking branch 'refs/remotes/ivan/feature/support-mate-polkit-agent' into develop
fix irc channel name
Merge remote-tracking branch 'refs/remotes/kali/irc-channel-fix' into develop
Use non blocking dialog for Pastebin result

With this change we no longer need to call the dialog with reactor.callLater.
Also removed useless failure.trap

Closes #5404.
Merge remote-tracking branch 'refs/remotes/ivan/bug/5404_pastebin-dialog-blocks-app' into develop
Hide mainwindow on quit and show tooltip.
Add flag to start the app hidden in the tray.

Closes #4990.
update requirements to last unified release
relax psutil version pinning

Closes: #5489
Merge remote-tracking branch 'refs/remotes/ivan/feature/hide-mainwindow-on-quit' into develop
Merge remote-tracking branch 'refs/remotes/ivan/feature/4990_start-hidden-flag' into develop
Merge remote-tracking branch 'refs/remotes/kali/update-reqs-to-unified' into develop
Merge remote-tracking branch 'refs/remotes/kali/bug/relax-psutil-pinning' into develop
Refactor EIPBootstrapper to the backend
Refactor out the ProviderConfig object retriever.
Move SRPAuth to the backend.

* Move methods from SRPAuth to backend: login, logout, change_password.

* Add backend section to hold temporary hack code, needed in the process
  of splitting frontend and backend.

* Replace pyside signals with Signaler signals.

* Move all the signaling and thread launching in SRPAuth inside of
  __impl.

* Move defer handling code (callbacks/errbacks) to the backend and left
  only signal handling in the GUI.

[Closes #5347]
Add changes file for #5347.
Remove PySide as a dependency.

- Use python `object` as a parent class.
- Replace QMutex with a `threading.Lock`
Keep track of backend's connected signals.