PID-File Management for Parallel Instance of DirWatch managed by NZBGet

[caronc]

Thanks to the great efforts of HugBug on this issue, it will be possible to spawn separate processes up in parallel to NZBGet. In addition to this, when NZBGet is reloaded, or restarts, this info will be passed along to our instance (by shutting it down).

In order to achieve this, an enhancement to our scripts need to be made so we can track a PID-File and prevent multiple instances of our process from spinning up at the same time.