add lxc-autostart support for sysv init systems

This change updates the way init scripts get installed so that more
than one init system can be supported. Instead of installing the
systemd service file from the spec file, it should be installed at
make install time, so that someone compiling from source also gets
the unit file installed.

Update the plamo template to use a lock file not named just
/var/lock/subsys/lxc since the presence of that file is used by
sysv init rc file to know if it should run the K01lxc script. This
also makes it consistent with the other templates which use
/var/lock/subsys/lxc-$template-name.

Signed-off-by: Dwight Engen <dwight.engen@oracle.com>
Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>