Added support for local message processing and some cleanups.

Added support for local message processing and some cleanups.
The local messages processing feature suggested by Unicontrols.
Driver can be directed by "processlocal" parameter to
distribute sent messages back to the local clients.
Values 0 .. disabled, 1 .. can be enabled by CANQUE_FILT IOCTL,
2 .. enabled by default, but can be specified on per queue as well.