sh/openrc-run.sh: expose default start/stop/status
sh/openrc-run.sh: expose default start/stop/status

Supervisor setups break easily when start/stop/status functions are not
default.

Applications that write multiple PIDs to a pidfile (eg HAProxy as
described in bug 601540), can also benefit from being able to call the
default start/stop/status with modified environment variables.

Expose the default start/stop/status functions as
default_start/stop/status, and use them for the defaults
start/stop/status.

Trivial usage example:
```
  stop()
  {
    t=$(mktemp)
    for pid in $(cat $pidfile) ; do
      echo $pid >$t
      pidfile=$t default_stop
    done
    rm -f $t
  }
```

X-Gentoo-Bug: 601540
X-Gentoo-Bug-URL: https://bugs.gentoo.org/601540
Signed-off-by: Robin H. Johnson <aa3b04a87f185a8b919ce94fe21b810489ffb8d4@gentoo.org>

dwfreed/openrc,OpenRC/openrc,dwfreed/openrc,OpenRC/openrc,dwfreed/openrc,OpenRC/openrc,williamh/openrc,williamh/openrc,williamh/openrc