MediaCrush/MediaCrush — pull request #587 by jleclanche (2014-04-30 22:15:00+00:00)
Title: Avoid downloading when Content-Length is bigger than MAX_SIZE

Continued from 60164a9. With this, we don't need to download anything
if we are dealing with a nice server that properly sets Content-Length.

Unfortunately, we still have to check during download as python-requests
does not abstract that bit away.