Added new programm to test the CAN filters in af_can.c .

Added new programm to test the CAN filters in af_can.c .
As the formerly test bench consisting of
- tst-filter-master.c
- tst-filter-server.c
- tst-filter-server.result
is pretty hard to use, this new tst-filter tool is intended to replace these
tools in the Linux test project LTP.

Together with tst-rcv-own-msgs, tst-filter is a complete new test bench then.

Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
git-svn-id: svn://svn.berlios.de//socketcan/trunk@1263 030b6a49-0b11-0410-94ab-b0dab22257f2