Removed old files
Switched to mimetypes (thanks, @Adysgit status)
Fixed up API, tests green again
Added unit tests for files
Added new daemon.py
Add current worker code
Made the queue FIFO (it was LIFO before)
Switched to celery
Made the frontend able to send tasks to the Celery queue.

The `processing_status` function in mediacrush/files.py has to translate Celery statuses to the strings we use in the API, for backwards compatibility.
Started working on processing scaffolding
Add  file
Support for all failure modes
Added all processors and streamlined files.py
Added more requirements, added a state to the API and moved invocation
Modified README
Removed  from mcmanage
Removed debug prints
Moved TimeLimitedCommand into Invocation
Add format detection via content inspection

This should allow us to confirm the integrity of files before starting
to process them. It will also allow us to support virtually every media
format under the sun.
Remove suggested mimetype

We do proper file inspection for everything, including ffprobe, so we
don't need to care about the user-supplied mimetype