Error checking

[apocatarsis]

We should add some error checking once in a while during the execution, to check if the device is still present (stopping/pausing the execution until it is back online) or has changed between the docking/plugged mode.

And we should also do error checking in every step of the initialization.

[Destroyer]

I think we can try to look for connected devices instead and if there're any and we are successful in opening them, we can continue execution. Ofc if the devices are plugged out we exit completly and after they're plugged back in systemd should start the daemon again (related to #20 ) .

Regarding inicialization I don't quite understand what do you mean. I think we're doing good job of providing error messages to the user during init. There're just few minor things that could be done differently - stoi exceptions aren't handled so if stoi fails the daemon goes down and parsing itself is not perfect. But rewriting it for this purpose is a waste of time for me right now.

[Destroyer]

Should be also fixed with #20 in Destroyer@55ce5a2

[RaulPPelaez]

Agree.