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

Rename 'name' to 'display_name'.
Recommend using Pillow instead of PIL.
Updated the assertion message of the ImageField.
Rephrased documentation changes according to feedback on IRC.
Merge pull request #1252 from thedrow/patch-3

Recommend using Pillow instead of PIL.
Fix TemplateHTMLRenderer example
Merge pull request #1256 from minddust/fix_docs_sample

Fix TemplateHTMLRenderer example
Adds pre_delete and post_delete hooks on
Merge pull request #1258 from pyriku/delete-signals-destroy-model-mixin

Adds pre_delete and post_delete hooks on `DestroyModelMixin`
Update release-notes.md
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