[NET]: Make lapbether work on 2.6.0-test3.

- unneeded include (no proc here)
- redundant fields in local device structure
+ convert to dynamic network device allocation
- refcounts on local data are redundant, it is really part of network_device
- excessive __inline__
+ correctly manage references to underlying network device
+ cascade unregister
+ use RCU and RTNL to avoid deadlock
+ account for bytes as well as packets