Add choices to options metadata for ChoiceField.
Add more context to the ChoiceField metadata.
Add unittests for ChoiceField metadata.

Rename 'name' to 'display_name'.
Merge pull request #1250 from Ian-Foote/choice_field

Add choices to options metadata for ChoiceField.
Update release-notes.md
Added @ian-foote, for work on #1250.  Thanks!
Remove Content-Type header from empty responses. Fixes #1196
Merge pull request #1265 from tomchristie/fix-1196

Remove Content-Type header from empty responses. Fixes #1196
Clarify wording, fixes #1133.
Merge pull request #1267 from tomchristie/fix-1133

Clarify wording, fixes #1133.
First pass on contribution guide
Merge branch 'master' of https://github.com/tomchristie/django-rest-framework
fix broken documentation links
Merge pull request #1269 from infecto/master

fix broken documentation links
Upgrade JSONP security warning.
Boilerplate cuteness
fix setup.py with new __init__.py boilerplate
Merge pull request #1270 from irrelative/master

fix setup.py with new __init__.py boilerplate
Raise appropriate error in serializer when making a partial update to set a required RelatedField to null (issue #1158)
Merge pull request #1272 from chuckharmston/1158-partial_relatedfield_null

Raise appropriate error in serializer when making a partial update to set a required RelatedField to null (issue #1158)