user abstractions, initial work

Also updated the default Feeder config file, and changed reserved variable names in http capability.

Some things I need to do:
- Find a way to create the ``users`` dict in the ``Hive`` class
- A ``HiveUser`` is basically an attribute of each Session. However, the value of this cannot be set in the ``create_session()`` method, since we can only associate the Session with a HiveUser after we obtain the username and password from the client. Find a non-complex workaround for this
- Update the Authenticator class to use the new ``HiveUser`` class.