mode_RPiHQ_mean.hpp: tidy up
mode_RPiHQ_mean.hpp: tidy up

RPiHQcalcMean() now returns the mean.
Removed debugLevel since it was redundant with the global debugLevel.
Clarified some comments.
Aligned values and comments.
thomasjacquin/allsky,thomasjacquin/allsky,thomasjacquin/allsky