- Privatised TTY constants, as they weren't being used elsewhere
- shifted imports slightly in Main
- TTY now has a constant defining serial timeout
- gpio_facade::get_unassigned_addresses() now returns a reference,
rather than a mutable reference, allowiing to remove a copy in Main
In no particular order:
- GPIO works now (finally)
- Threading works properly
- Direct serial communication seems to be working properly. Parsing of
serial responses is going to take some adjustments...
OutputPin objects aren't Copy- or Clone-able, which is causing problems.
Starting rewrite, passing around u8 OutputPin *addresses* instead,
hopefully that will work properly.
