Re-introduce the old lxc-ls script and manpage under a new legacy
sub-directory.

Those will be installed in place of their python equivalent when LXC
is built without --enable-python.

Any other script ported to python should be added to those lists.
Signed-off-by: Stéphane Graber <stgraber@ubuntu.com>
Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>