daemon status check

Fix for status check error https://github.com/emonhub/emonhub/issues/27
Revert "daemon status check"

This reverts commit 9bd53b6325e9e01380e79ff2a15edc1526520e89.
daemon status check

Better fix for https://github.com/emonhub/emonhub/issues/27. Reports if
process is missing PIDFILE data and if process has ended and not removed
PIDFILE.
daemon commands and messages

Significant changes to init script were needed to give better status &
error reporting, because standard start-stop-daemon didn't cope well
with python scripts when pidfile not available or process had stopped
without deleting pidfile.
This resolves issues https://github.com/emonhub/emonhub/issues/23