Remove and replace usage of "mongo" by "mongoClient". This involves xsd schema, bean names, constructor and parameter types. This required some API changes as some server commands are no longer directly available through the api, but have to be invoked via runCommand.
Also remove references to outdated API using Credentials and an authentication DB instead of MongoCredentials for authentication.
Updated and removed (unused) tests; Altered documentation.
Original pull request: #451.