Initial import

Fixes to satellite model
T/F to TRUE/FALSE
Bug in model specification
Bug in shearwater binning

The shearwater example was creating one bin too many.
Relaxed constraints in Modified models

The constraints on missing twilights in the modified models have been
relaxed.  This is consistent with the intention of the modified models,
and should only make an impact at very high latitudes.
Bugfix

Corrected constraints in the modified models.
Added Citation file

Imported the CITATION file from SBW.
stray SBW
Merge branch 'master' into Pimage01