In the Python implementation users could pass a regex without a parameter flag
as additional argument on the command line. The C implementation gained the
flag -r/--regex for this. To not irritate users we restore the old behaviour
and additionally rename -r/--regex to --filter to allow eplicitly passing the
regex.
Signed-off-by: Christian Brauner <christian.brauner@mailbox.org>
Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>