New all-singing, almost all dancing, csv output module.

New all-singing, almost all dancing, csv output module.

 - It now handles more than one analog value correctly - at least from the
   demo driver.
 - Add column headers from channel names.
 - Add a row dedup capability.
 - Add a sample time column.
 - Add a frame end formatting (for gnuplot).
 - Made almost all formatting controllable or at least optional.
 - Fix it so we can mix analog and digital values.
 - Add outputting a gnuplot script for the data.
 - Count actual channels, not just mine, to find end of sample.
 - Add trigger option (untested).