Shutdown GUI when exit is requested externally

[Flozza]

The client does not properly shut down right now (e.g. the GUI does not exit, etc.). If an exit is requested, the GUI should shut down as well.

[Flozza]

Fix #42 and improve some setup stuff

We use some dirty hacks here but at least it makes the startup more stable.

→ <<cset 74a80ac5af4e>>