Remove `dbgd_reboot`?

[JayFoxRox]

Just by looking at the code, this looks pretty bad. dbgd_reboot should just set a flag and the mainloop should then reboot after nicely shutting down.

[mborgerson]

It's not very clean but I think it's only a minor issue atm.

[JayFoxRox]

We should drop reboot entirely because of #6 . If we can call any kernel function rebooting can be done through those. The only benefit of integrating it as a seperate command is that we can close the connection nicely. (But we might get away with some callback registration or something?)