rename -> DiffuseElement

Base/Pixel/DiffuseElement.cpp

Base/Pixel/DiffuseElement.h

Core/Computation/DWBAComputation.cpp

Core/Computation/DWBAComputation.h

Core/Computation/IComputation.cpp

Core/Computation/IComputation.h

Core/Computation/SpecularComputation.cpp

Core/Element/SpecularElement.cpp

Core/Element/SpecularElement.h

Core/Scan/AngularSpecScan.cpp

Core/Scan/AngularSpecScan.h

Core/Scan/ISpecularScan.h

Core/Scan/QSpecScan.cpp

Core/Scan/QSpecScan.h

Core/Simulation/DepthProbeSimulation.cpp

Core/Simulation/DepthProbeSimulation.h

Core/Simulation/GISASSimulation.cpp

Core/Simulation/GISASSimulation.h

Core/Simulation/ISimulation.cpp

Core/Simulation/ISimulation.h