add tests using a bunch of behavioral variants
  * add options to dummy driver to switch all the driver_info flags
  * add bitmap_sublist to test util .. returns bitmap-selected sublist
  * add 'unique' option for driver property_info -- makes normalization
    uniqify properties; dummy driver uses this
  * in erbi_connection_test:
    * setup get_select & fetch_conn to take driver proplists
    * create collection of variant configs for dummy driver, using bitmap_sublist
    * run the selectall_test_ tests over all 64 config variants