[PATCH] Another big 6pack patch

Below another 6pack patch which I've got sitting in my repository for a
while already.  The patch does:

 o Update my callsign
 o Cleanup the internal for synchronization with a 6pack TNC a little bit
   so it won't result in heaps and piles of messages in syslogs as it used
   to do.
 o Does paranoia checks for the maximum allowable packet size on transmit.
   There was a slight chance this might have resulted in a crash in just
   the right configuration.
 o Verifies the address family for the SIOCSIFHWADDR network interface
   ioctl.
 o Tries to do proper locking so nothing will access dev->dev_addr in
   midflight while changing the layer 2 address.
 o Uses an intermediate buffer for the SIOCSIFHWADDR ioctl so an error in
   copy_from_user can't result in a half-modified MAC address.
 o Swaps the arguments of decode_prio_command, decode_std_command and
   decode_data such that for consistency the struct sixpack pointer will be
   the first argument like everywhere else.
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>