mv Integrator to cpp files

Core/Aggregate/IInterferenceFunction.cpp

Core/Aggregate/IInterferenceFunction.h

Core/Aggregate/InterferenceFunction2DLattice.cpp

Core/Aggregate/InterferenceFunction2DLattice.h

Core/Aggregate/InterferenceFunction2DParaCrystal.cpp

Core/Aggregate/InterferenceFunction2DParaCrystal.h

Core/Aggregate/InterferenceFunction2DSuperLattice.cpp

Core/Aggregate/InterferenceFunction2DSuperLattice.h

Core/Aggregate/InterferenceFunctionFinite2DLattice.cpp

Core/Aggregate/InterferenceFunctionFinite2DLattice.h

Core/Aggregate/InterferenceFunctionHardDisk.cpp

Core/Aggregate/InterferenceFunctionHardDisk.h

Core/Correlations/FTDistributions2D.cpp

Core/Correlations/FTDistributions2D.h

Core/Correlations/IPeakShape.cpp

Core/Correlations/IPeakShape.h

Core/HardParticle/FormFactorCone.cpp

Core/HardParticle/FormFactorCone.h

Core/HardParticle/FormFactorHemiEllipsoid.cpp

Core/HardParticle/FormFactorHemiEllipsoid.h