Reworked the fileprovider to proxy data directly from the provider
rather than attempt to funkily redirect when needed, since it was overly
complex and wouldn't work well in the long run. Temporarily added "file"
as constant return for determining the filetype through Backblaze.
Added a Makefile to make life easier as well, and rewrote the README to
reflect the refactor/rewrite and new approach to providers.