Fix Django 1.6 support, use new `django.conf.urls` import path.
Bump version numbers for new release, update setup.py
Fix deprecation warning from django-polymorphic

Only support django-polymorphic >= 0.4.2, hence the workaround
for older versions can be removed which also removes the deprecation warning.

Fixes: #6
Fix broken 1.3 support
Set version to 0.8.8
Workaround for issue #2, temporarily disable pagination.
Bump versions
Use json from standard python 2.6 library

Fix Django 1.6 deprecation warning
Hide the "add" icon when there is no permission
Bump versions
Update changelog
Merge pull request #2 from edoburu/master

latest from Diederik