Cleanup '.model' shortcut from code and docs

Update filtering.md

Updated links for django-guardian package.

 ManyRelatedField.get_value clearing field on partial update

Use the proper db_table argument when constructing meta

Reload api_settings when using Django's 'override_settings'

Release notes for 3.0.4

A PATCH to a serializer's non-related CharField was clearing an ancillary StringRelatedField(many=True) field.
The issue appears to be in the ManyRelatedField's get_value method, which was returning a [] instead of empty
when the request data was a MultiDict.

This fix mirrors code in fields.py, class Field, get_value, Ln. 272, which explicitly returns empty on a partial update.

Tests added to demonstrate the issue.

typo in fields.md

minor typo in viewsets docs

Pass {} as data to DataAndFiles, as it ends up in a MergeDict

In the same vein as #2399.

Added DictField and support for HStoreField.

Added UUIDField.

Update Django-Filter references

Support 1.8-alpha.