Added GenericForeignKey support.
Thanks for the original patch @achur (Alex Churchill)
Thanks for reporting @tiabas (Kevin Mutyaba), @dhatch (David Hatch)
Thanks @joshbodhe and @toastdriven for the code review and support.

Closes Issue #101
Closes Issue #191

This was resolved and added with issue #620.

Squashed commit of the following:

commit eb87af0802a24d56930a4749a637ca9c095339d5
Author: Issac Kelly <issac.kelly@gmail.com>
Date:   Mon Aug 27 22:58:16 2012 -0700

    Remove unused file and empty tests file. Resources are tested via the fields.py file

commit 00453c1f9ca650e673aa7af56796d5228f946d55
Author: Issac Kelly <issac.kelly@gmail.com>
Date:   Mon Aug 27 22:53:24 2012 -0700

    Whitespace

commit 67298f452fe5c31df11b4b6e8a931cce2dec22c1
Author: Issac Kelly <issac.kelly@gmail.com>
Date:   Mon Aug 27 22:39:44 2012 -0700

    Add Docs.

commit 179ab3fb279dbc6d9b9f75db9195606a22aebdca
Author: Issac Kelly <issac.kelly@gmail.com>
Date:   Mon Aug 27 21:17:10 2012 -0700

    Fix field init tests. Thanks Josh Bohde

commit 7b3707801d6c74b828bd19c02d2c5039ee8f10b4
Author: Issac Kelly <issac.kelly@gmail.com>
Date:   Mon Aug 27 21:00:29 2012 -0700

    Whitespace cleanup and comments.

commit 02988b04443fca9d3f6e00d7ea39d9def6897459
Author: Issac Kelly <issac.kelly@gmail.com>
Date:   Mon Aug 13 23:28:01 2012 -0700

    WIP contenttypes/GFK integration.

    Needs:
    more thought about tests
    code review
    release notes
    documentation
    gracious thanking of the people who helped
    Python 2.5 solution for context managers in tests.
Adjusted AUTHORS for dstufft.
Fixed a bug in ``DecimalField`` where the value may not be properly coerced.
+ LocalWiki for who uses.
Added i-am-cc.org to Who Uses.
Used dict.pop to replace four lines of code with one.
Adding tests for obj_update with identifiers

This test exercises obj_update when grabbing an object using its uri
identifiers.

Currently lines 1915-1934 cover this special case and there is no
test case for them. If you comment out those lines and run the whole
test suite, it will pass.
Sending PUT requests should now be much more efficient,
as ``full_hydrate`` is no longer called twice. Thanks to
maraujop for most of the work!
Vastly improved the ``Vary`` & ``Cache-control`` headers &
hence improved how cacheable GET requests are. Thanks to
ross for the original patch.
Fixed an import error in tests. Thanks to dirn for the report!
Fix a bad cherry-pick and make tests pass again
Remove AdminMediaHandler.

AdminMediaHandler was removed in Django 1.5.
Add dev builds to travis.
Added 'hammock' to 'docs/tools.rst'
Add content types to setup.py, Fixes a bug reported in IRC by berndt
Try/Except for import of constant which was moved for django 1.5

Closes #671
Added a contributing doc for bonus GH integration.
Fixed simple typo in "The Hydrate Cycle" section.
Django dev JSONSerializer is now based on json

Djando dev breaks Tastypie serialization. Tastypie uses Django
`json.JSONEncoder`, which was based on simplejson in previous versions,
but it's now based on json, which doesn't accept a keyword argument
`namedtuple_as_object` anymore.

So in Django 1.5 we need to pass `JSONEncoder` to json, instead of
simplejson
Merge pull request #676 from hroart/patch-1

Fixed simple typo in "The Hydrate Cycle" section.