Add `mimeparse.py` from `nalanda-rct3` because `tastypie` needs it.
Merge branch 'release-0.12.0' into hotfix/add-mimeparse-py
Merge pull request #2420 from mrpau/hotfix/add-mimeparse-py

Add `mimeparse.py` from `nalanda-rct3` because `tastypie` needs it.