Merge branch 'tidy-operator-with-multple-component' into 'master'

Field.hpp

MemoryRegionCPU.hpp

Operators/Helmholtz/HelmholtzCUDA.hpp

Operators/Helmholtz/HelmholtzStdMat.hpp

Operators/IProductWRTDerivBase/IProductWRTDerivBaseCUDA.hpp

...ators/IProductWRTDerivBase/IProductWRTDerivBaseStdMat.hpp

Operators/Operator.hpp

Operators/OperatorIProductWRTDerivBase.hpp

Operators/OperatorPhysDeriv.hpp

Operators/PhysDeriv/PhysDerivCUDA.hpp

Operators/PhysDeriv/PhysDerivStdMat.hpp

main.cpp

run/hex.xml

run/prism.xml

run/pyr.xml

tests/init_fields.hpp

tests/init_physderivfields.hpp

tests/test_physderiv.cpp

tests/test_physderivcuda.cpp