* Old struct ieee80211_meshpeer_ie had wrong peer_proto field size;
* Added IEEE80211_MPM_* size macros;
* Created an enum for the Mesh Peering Protocol Identifier field according
to the standard spec and removed old defines;
* Abbreviated Handshake Protocol is not used by the standard anymore;
* Modified mesh_verify_meshpeer to use IEEE80211_MPM_* macros for verification;
* Modified mesh_parse_meshpeering_action to parse complete frame, also to parse
it according to the standard spec;
* Modified ieee80211_add_meshpeer to construct correct MPM frames according to
the standard spec;
Approved by: adrian