Removed unnecessary copy of SimulationElement vector in MainComputation

Core/Computation/IComputationTerm.h

Core/Computation/MainComputation.cpp

Core/Computation/ParticleLayoutComputation.cpp

Core/Computation/ParticleLayoutComputation.h

Core/Computation/RoughMultiLayerComputation.cpp

Core/Computation/RoughMultiLayerComputation.h

Core/Computation/SpecularComputation.cpp

Core/Computation/SpecularComputation.h

Core/Simulation/GISASSimulation.cpp

Core/Simulation/GISASSimulation.h

Core/Simulation/OffSpecSimulation.cpp

Core/Simulation/OffSpecSimulation.h

Core/Simulation/Simulation.cpp

Core/Simulation/Simulation.h

auto/Wrap/doxygen_core.i

auto/Wrap/libBornAgainCore.py

auto/Wrap/libBornAgainCore_wrap.cpp