Added Device.reload() to reload the proxy every time the device mode is
changed. Added Device.set_mode() and partial implementation of
Device.start_adhoc_open().
Added link to meaning of hack in HACKING.md
They won't work yet but when they do we can use the classes in iwd.py
instead of using dasbus directly. Also added a Name to Match in
systemd-networkd/06-eth.network