Create .pid files for package builds

To properly support OS startup / shutdown scripts (sysvinit for example) we would like to enable the creation/deletion of .pid files.  The issue with .pid creation in the init files (as is standard) is the system can get into a bad state if for example init is used for runner startup, but then ./runner stop is used for shutdown.  

This PR attempts to address that by creating the .pid files in the runner script itself.  No attempt was made to make this setup work for devrel (multi-node, single machine) builds because those are typically run as non-root.