2.4.0 Release.

### 2.4.0

* Use py.test
* `@detail_route` and `@list_route` decorators replace `@action` and `@link`.
* `six` no longer bundled.  For Django <= 1.4.1, install `six` package.
* Support customizable view name and description functions, using the `VIEW_NAME_FUNCTION` and `VIEW_DESCRIPTION_FUNCTION` settings.
* Added `NUM_PROXIES` setting for smarter client IP identification.
* Added `MAX_PAGINATE_BY` setting and `max_paginate_by` generic view attribute.
* Added `cache` attribute to throttles to allow overriding of default cache.
* Bugfix: `?page_size=0` query parameter now falls back to default page size for view, instead of always turning pagination off.

Needs more detailed release notes.