Use the NC_FILL_VALUE in stats if the filtercount is equal to zero, this
allows tools that respect the FillValue attribute to handle the data
much better. Matplotlib can make the proper averaging profs now.
Improve plotting script for BOMEX to use all filters
Forgot to calculate the fields in the tmp arrays
Added the buoyancy to the stats
Improvements on core statistiscs
Merge remote-tracking branch 'chiel/stats' into stats

Conflicts:
	src/thermo_moist.cxx
Give user control of line color and styles
Merge remote-tracking branch 'chiel/stats' into stats
Better colorscheme, and w statistic