Improve file type detection/handling.
Merge branch 'master' of github.com:CIRB/django-fixmystreet

# By Jonathan Sanchez Pando
# Via Jonathan Sanchez Pando
* 'master' of github.com:CIRB/django-fixmystreet:
  improve orrdering and selection of admin UI FMS-290
  make history works and perf improvement on admin report FMS-290