auto-discovery poc, local process discovery

[portertech]

This is an auto-discovery proof of concept. This pull-request demonstrates how easy it is to discover local processes, filter the process list, and create the appropriate collector tags in order to drive Sumo platform "insights" (e.g. "We've noticed that these hosts are running MySQL, would you like to install the Sumo MySQL app to monitoring them?").

This POC depends on the WIP metadata API.. The code currently produces auto-discovery tags like these on my development host:

{
  "sumo.disco.enabled": "true",
  "sumo.disco.docker": "running",
  "...": "..."
}

[portertech]

Closing in favour of #893