Stop using deprecated Connection class

Connection has been deprecated for the benefit of MongoClient. Updating
this module to use it instead.

ref: http://api.mongodb.org/python/current/api/pymongo/connection.html
Merge pull request #1 from ferrix/client

Stop using deprecated Connection class
Authenticate to the database

If both `MONGODB_USERNAME` and `MONGODB_PASSWORD` are set, authenticate
the connection. Also use Database as described in the documentation.

ref: http://api.mongodb.org/python/current/api/pymongo/database.html
Document the optional authorization parameters

Having these in the documentation helps people find them.
Merge pull request #2 from ferrix/client

Authenticate to the database
Added contributors section + thanks @ferrix
Merge branch 'client' of git://github.com/ferrix/tastypie-mongodb-resource into ferrix-client

Conflicts:
	README.md