Adding documentation for the new M= option which limits Coccinelle
to a specific set of directories.
Signed-off-by: NGreg Dietsche <Gregory.Dietsche@cuw.edu>
Acked-by: NJulia Lawall <julia.lawall@lip6.fr>
Signed-off-by: NMichal Marek <mmarek@suse.cz>