Regression test for #1072
Handle case where obj=None in PKRelatedField.field_to_native()

Fixes #1072
Merge pull request #1077 from tom-leys/patch-2

Updated tutorial part 6: 2 examples were missing includes
Merge pull request #1078 from yprez/fix_1072

Fix empty serializer bug
Add windows virtualenv activate instruction

Closes #1075.
Changed DOAC documentation link
Merge pull request #1081 from kevin-brown/doac_docs_link

Updated DOAC integration link
Added test for OPTIONS before object creation from a PUT
Tiny typo fix
Merge pull request #1084 from thetylerhayes/master

Tiny typo fix
Merge pull request #1076 from edmondwong/master

Allow OPTIONS to retrieve PUT field metadata on empty objects
Added @edmundwong for work on #1076.  Thanks!
Fix typo
added guardian as optional requirement, stubbed out object-level permission class
some properly failing tests, set up for standard permissions
Support customizable view EXCEPTION_HANDLER

Add `api_settings.EXCEPTION_HANDLER` to support custom error responses.

Fixes #907.
Add EXCEPTION_HANDLER docs to exception docs
Merge pull request #1092 from rouge8/custom-exception-handler-setting

Support customizable view EXCEPTION_HANDLER (#907)
Extra docs on custom exception handling.
necessary test settings for guardian