don't pass sample if only roughness is needed

Core/Computation/SpecularComputation.cpp

Core/Term/SpecularTerm.cpp

Core/Term/SpecularTerm.h

GUI/Models/BeamAngleItems.cpp

GUI/Models/BeamWavelengthItem.cpp

GUI/Models/TransformToDomain.cpp

Resample/Processed/ProcessedSample.cpp

Resample/Processed/ProcessedSample.h

Resample/Specular/SpecularStrategyBuilder.cpp

Resample/Specular/SpecularStrategyBuilder.h

auto/Wrap/doxygenCore.i

auto/Wrap/doxygenResample.i