get all unit tests passing
  * fix lots of bugs in dummy driver and test code
  * and a few fixes of actual code:
    * remove try/catch in erbi:connect
    * erbi_driver:call all devolves to one base case
    * refactor row/col adding in erbi_driver
      now promotes bare column names to #erbdrv_field records
    * strip out a bunch of io:format()s