Update docs/who_uses.rst

Added dbpatterns to who uses
If no object_class is present, do not try to instantiate an object when building the bundle. This does not affect model-based resources; however, the assumption that had been made that an object_class is always going to be present is not valid when using custom Resource objects that are not necessarily model-based.
Adding OAuth 2.0 tutorial information in cookbook
Ignore the env3 virtualenv.
Backfilled release notes.
Added release notes for v0.9.15.
Bumped version to v0.9.15!
Started v0.9.16-dev.
Unprocessable entity http code
Merge pull request #812 from fatiherikli/patch-1

Added dbpatterns to the Who Uses docs.
Add (failing) test for unicode support in Resource.method_check
Support unicode HTTP method names in Python 2.x (fixes toastdriven/tastypie#935)
Merge pull request #936 from kennknowles/unicode-upper

Support unicode HTTP method names in Python 2.x
added None value for username_field when ImproperlyConfigured
error occurs so it wont give an ImportError
add detail_uri_name to Non-PK URL example

This is a crucial detail missing that ought to be included in the example. The resource_uri generated from the example and included in the response is inherently incorrect, given the desired result. EG, if you want to use a non-pk you want to query a ModelResource like this, you'll want the resource_uri updated. If you don't, hopefully you'll notice that the example includes meta.detail_uri_name :)
fixes #959, Authorization calls create_detail twice
Update docs/paginator.rst with a warning and an example solution, to avoid unnecessary and possibly inefficient database queries; closes #973.
Merge pull request #975 from ikatson/paginator-estimated-count

Update docs/paginator.rst, closes #973 (possible inefficient calculation of "total_count")
Added test case to demonstrate resources without object_class defined failing on build_bundle
Made proper test for checking Resource objects without a defined object_class.