Closes #97 - Create Range class for Fluo API

Pull request for #97
There was discussion on this.  The reasoning is that we want to move completely away from any external dependencies in the API.  Using data classes from Hadoop or Accumulo like Text or ByteSequence makes the API dependent on outside libraries.  This can also cause problems if the API for Text or ByteSequence is changed.  @keith-turner may be able to add more reasoning/context.