----------------
* Fixed and improved ``command`` method from ``Database`` class using
``OrderedDict``.
* Added support for ``last_status``, ``previous_error``, ``error``,
``reset_error_history``, ``profiling_level`` and ``set_profiling_level``
methods to ``Database`` class.
* Added support for ``distinct``, ``reindex`` and ``find_and_modify`` methods
to ``Collection`` class.
* Added ``helpers`` module.
* Added UTF-8 support for REST API requests.
* Support for new API key format.