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
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
first pass at object level permissions and tests
switch to a dedicated filter for read list object permissions
removed unnecessary guardian req and view.action parsing
better doc for object permissions, drop redundant has_permission call