* Make downloaders subclass of base_downloader.py
* Link engines and downloaders together for all engines
* Replace / merge worker_factory.py with engine_manager.py
* Fix issue with engine not being available to download
* Add version caches to ffmpeg downloader
* Remove some test parameters
* "releases" should be "release" in linux ffmpeg url
* CPU was incorrectly reported as OS
* Fix naming structure for FFMPEG downloads for linux
* More linux ffmpeg work
* Improved error handling
* WIP
* Consolidate platform reporting to not use platform directly
* Fix missing folder name
* Fix project output naming
* Undo config.yaml commit
* Add is_engine_available API call
* Fix issue where subjobs would not find servers