Some binaries in can-utils depend on features in the socket-can svn

Some binaries in can-utils depend on features in the socket-can svn
repository. Building with exported headers from an unpatched kernel will
fail due to missing symbols or headers.

This patch adds two make variables to optionally disable building such
binaries, like this:

make PROGRAMS_ISOTP= PROGRAMS_CANGW= PROGRAMS_SLCAN= all

Signed-off-by: Olaf Hering <olaf@aepfle.de>
Signed-off-by: Oliver Hartkopp <oliver@hartkopp.net>
git-svn-id: svn://svn.berlios.de//socketcan/trunk@1163 030b6a49-0b11-0410-94ab-b0dab22257f2