Fixed url that was returned by resource in return structure.  Also, added error message for when md5s are entered but none are found in the database.  And, changed the behavior.  Before if no md5s were sent in md5s_to_read_sequences call, all sequences were returned.  Fixed this by doing a check before making that call.  Lastly, included only valid md5s in returned url.
Merge pull request #225 from jaredbischof/develop

Fixed url that was returned by resource in return structure.  Also, adde...