Added an option to get related resource_uri with polymorphic resources
Includes basic tests
Use an additional mixin for get_related_resource
Changed meta property name to prefer_polymorphic_resource_uri
Added a few documentation
Check if resource is registered or don't override resource_name.
Added some tests for this purpose
In MongoEngine 0.8, query operators will be exposed through this module.
Merge pull request #38 from leo-naeka/related_resource_name

Option to get related resource_uri with polymorphic resources
Merge branch 'master' of github.com:mitar/django-tastypie-mongoengine
Merge branch 'master' into django-tastypie-0.9.12
Updating to 0.9.12.