Expand tests over django 1.7
Add tests for deconstruct method
Add deconstruct method for Django 1.7

Django 1.7 expects a deconstruct method on custom fields to help with migrations. https://docs.djangoproject.com/en/1.7/howto/custom-model-fields/
Update test settings to 1.7 template

Getting the check warnings to quiet down
Add an explicit ModelForm.fields specification
Merge branch 'django-17-support' into develop