Merge remote-tracking branch 'upstream/develop' into ComboProperty

Core/Multilayer/LayoutStrategyBuilder.cpp

Core/Multilayer/LayoutStrategyBuilder.h

Core/Multilayer/MultiLayer.cpp

Core/Multilayer/MultiLayer.h

Core/Particle/IParticle.cpp

Core/Particle/IParticle.h

Core/Particle/ParticleComposition.cpp

Core/Particle/ParticleComposition.h

Core/Particle/SlicedFormFactorList.cpp

Core/Particle/SlicedFormFactorList.h

Tests/UnitTests/Core/Sample/MultiLayerTest.h

Tests/UnitTests/Core/Sample/ParticleCompositionTest.h

Wrap/swig/ignores.i

auto/Wrap/libBornAgainCore.py

auto/Wrap/libBornAgainCore_wrap.cpp

auto/Wrap/libBornAgainFit_wrap.cpp