Ensemble photometry for Data Set 19

[Andrew Bennett <andrew.bennett@ns.sympatico.ca>]

I have finally got the first prototype program
selecting ensembles and doing photometric
calibration on this data set.

Initial results looking good except that I have
set rather stringent conditions for ensemble
selection ... the first successful run threw out 
all but 45 stars! That's an improvement on the 
previous version which refused to select any ensembles
and threw out all the stars. I will keep the 
group posted.

Andrew Bennett, Avondale Vineyard