* Added IEEE80211_MESH_MAX_NEIGHBORS and it is set to 15, same as before;
* Modified mesh_parse_meshpeering_action to verify MPM frame and send
correct reason code for when a frame is rejected according to standard spec;
* Modified mesh_recv_action_meshpeering_* according to the standard spec;
* Modified mesh_peer_timeout_cb to always send CLOSE frame when in CONFIRMRCV
state according to the standard spec;
Approved by: adrian