* Adds method to improve cleanup of empty directories
* resolved bug where source metadata worker could call itself in an infinite loop
* Refactored file deletion for media items
* Removed useless filesystem data worker
* Updated task listing fns to take a record directly
* Refactored the way I call workers
* Improved some tests
* [WIP] break out a few contexts, start refactoring fast index modules
* [WIP] more contexts, this time around slow indexing and downloads
* [WIP] got all tests passing
* [WIP] Added moduledocs
* Built a genserver to rename old jobs on boot
* Added a module naming check; moved things around
* Fixed specs
* Bumped up the line length because I fear no man
* Refactored indexing
Previously, indexing worked by collecting the video IDs of only videos
that matched indexing criteria. This new model instead stores ALL videos
for a given source, but will only _download_ videos that meet that criteria.
This lets us backfill without indexing, makes it easier to add in other
backends, lets us download one-off videos for a source that don't quite
meet criteria, you name it.
* Updated media finders to respect format filters; Added credo file
