include djangorestframework-httpsignature in the docs
Merge pull request #1433 from etoccalino/http-signature

include djangorestframework-httpsignature in the docs
Link to DRF-extensions. Refs #1430
Minor docs example fix

Dates are smaller when they happen before.
Merge pull request #1436 from meshy/patch-1

Minor docs example fix
Demonstrate problem post/put'ing serialized data that contains 'None'
Display the media type of the API response on the browsable API
Update Travis to test Django 1.6.2

We should be testing the latest version of Django 1.6 as we're doing in the other 1.x releases.
Allow 'None' to pass as a null value in RelatedFields
handle negative time value and prevent a divide by zero
Merge pull request #1440 from un33k/master

handle zero and negative available_requests
Merge pull request #1441 from dustinfarris/null-serialization

TestCases and POST/PUT'ing serialized data that contains `None`
Merge pull request #1443 from silent1mezzo/patch-1

Update Travis to test Django 1.6.2
Merge pull request #1437 from Keats/master

Display the media type of the API response on the browsable API
clarified which urls.py to edit
Merge pull request #1444 from DanSears/master

clarified which urls.py to edit