rewrite interrupt handler as thread class

This approach moves the interrupt wait logic into it's own thread.

This does not yet work as the previous solution did not too. The
previous solution didn't actually register the interrupt. The new
one does try to register the interrupt but fails, since the line is
already bound as an input type from the pin init method before the
interrupt is called. Tried approaches to free the pin before trying to
bind it again or to find out if the input should be an interrupt did
not work yet.