Use info from getlasterror whether a document has been updated or created.
Fix ReferenceField dbref = False
Updated travis.yml
Fixed objectId for DBRef
Improved import cache
Fixed reload issue with ReferenceField where dbref=False (MongoEngine/mongoengine#138)
Moved injection of Exceptions to top level
Initial support to Group and Permission. The /admin can't be exec login in MongoDB yet. Only SQLsDB (SQLite,...)

This code work with django-mongoadmin pluggin.
Updated docs thanks @mitar
Merge branch 'master' into 0.7
Added CONTRIBUTING.rst
Updates to the readme
can now use AuthenticationBackends with permissions.
Adding, adjust and transplant more methods to auth.User model
exposing mongoengine.django module
Merge pull request #573 from garrypolley/master

Allow Django  AuthenticationBackends to work with Django user

Thanks @garrypolley
Merge branch 'master' of github.com:hmarr/mongoengine
Added Garry Polley to contributors list

hmarr/mongoengine#573
Updated URLField

handle unicode and custom validator (MongoEngine/mongoengine#136)
Fix loop