Merge pull request #1 from tomchristie/master

Update from main
Merge pull request #2 from tomchristie/master

Update to latest
Merge pull request #3 from tomchristie/master

Update to latest
add transform_<fieldname> methods to serializers, which basically do the opposite of validate_<fieldname> on a per-field basis.
Allow OPTIONS to retrieve PUT field metadata on empty objects

This allows OPTIONS to return the PUT endpoint's object serializer metadata when the object hasn't been created yet.
Added test for OPTIONS before object creation from a PUT
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
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.
Update release-notes.md
Add order_by to the AutoFilterSet

`AutoFilterSet` should contains `order_by` set to all by default.
Merge remote-tracking branch 'upstream/master'
Merge branch 'master' of git://github.com/bwreilly/django-rest-framework into bwreilly-master
Tweaks and docs to object-level model permissions.
Updated release notes
Add Django Guardian to travis testing