We'll replace this primarily with per-realm quotas (plus the simple
per-file limit of settings.MAX_FILE_UPLOAD_SIZE, 25 MiB by default).
We do want per-user quotas too, but they'll need some more management
apparatus around them so an admin has a practical way to set them
differently for different users. And the error handling in this
existing code is rather confused. Just clear this feature out
entirely for now; then we'll build the per-realm version more cleanly,
and then we can later add back per-realm quotas modelled after that.
The migration to actually remove the field is in a subsequent commit.
Based in part on work by Vishnu Ks (hackerkid).
Greg Price
Brock Whittaker
Cory Lynch
Philip Skomorokhov
Umair Khan
Leo Franchi
Tim Abbott