Add address masks to BSSID lists

Add address masks to BSSID lists

In many applications it is useful not just to enumerate a group of well
known access points, but to use a address/mask notation to match an
entire set of addresses (ca:ff:ee:00:00:00/ff:ff:ff:00:00:00).

This change expands the data structures used by MAC lists to include a
mask indicating the significant (non-masked) portions of an address and
extends the list parser to recognize mask suffixes.

Signed-off-by: Stefan Tomanek <stefan.tomanek@wertarbyte.de>