Guide to implementing a new runner + Python runner for PArSEC

[maurermi]

This is a Python-based runner and a corresponding guide for adding a new runner. The goal of this extension is to make development of new runner environments more straightforward.

Also embedded here are a script for running the Lua bench test, a ticket logging mechanism for reporting the status of tickets seen by a broker, and a get_row utility for reading directly from the shards. These could be split out into a separate PR if helpful.

Note (for reviewers): This introduces a dependency on Python developer tools. I think it's worth considering making this a separate branch or repository as a result.

[maurermi]

Will address the linting errors shortly

[HalosGhost]

Needs rebase.