Revert "Merge pull request #1355 from dimagi/revert_django-1.5-compat"

This reverts commit 1e998fdc78c72b540da8506a5a1c4a6ea7f19a5e, reversing
changes made to cb6bfbf3fb773f665af6dbc98ce1eab49cb65be7.
Merge pull request #1366 from dimagi/django-1.5-compat-reapply

Revert "Merge pull request #1355 from dimagi/revert_django-1.5-compat"