Lists of counts had pervaded every corner of CrystFEL, being used as markers
for the presence of reflections.  Now we have a better way of doing this,
the ReflItemList, and few parts of the suite apart from process_hkl have any
business knowing how many observations were made of a particular reflection.

More advanced merging methods make it slow... :(

process_hkl: don't write output in results/, improve error message, output ZA with --no-analyse --zone-axis

	s convention
	detector geometry
	comments, help messages