new base class IModel, for use in Material

Core/Export/SampleLabelHandler.cpp

Core/Export/SampleLabelHandler.h

Param/Base/IModel.h

Param/Base/IParameterized.h

Sample/Material/Material.h

Wrap/swig/fromParam.i

Wrap/swig/libBornAgainParam.i

auto/Wrap/doxygenCore.i

auto/Wrap/doxygenParam.i

auto/Wrap/libBornAgainCore_wrap.cpp

auto/Wrap/libBornAgainParam.py

auto/Wrap/libBornAgainParam_wrap.cpp

auto/Wrap/libBornAgainParam_wrap.h

auto/Wrap/libBornAgainSample.py

auto/Wrap/libBornAgainSample_wrap.cpp