#839 Utilities/Numeric: use a dedicated namespace for the free functions defined there.

Sources/Core/TimeManager/Policy/ConstantTimeStep.hxx

Sources/FiniteElement/FiniteElementSpace/FEltSpace.hpp

...iteElementSpace/Private/Impl/AttributeProcessorHelper.cpp

Sources/FiniteElement/Nodes_and_dofs/Dof.cpp

Sources/FiniteElement/Nodes_and_dofs/Dof.hpp

Sources/FiniteElement/Nodes_and_dofs/Dof.hxx

Sources/FiniteElement/Nodes_and_dofs/LocalNode.hxx

Sources/FiniteElement/Nodes_and_dofs/NodeBearer.cpp

Sources/FiniteElement/Nodes_and_dofs/NodeBearer.hxx

.../FiniteElement/QuadratureRules/GaussQuadratureFormula.hxx

...lement/QuadratureRules/Private/GaussQuadratureFormula.cpp

...FiniteElement/RefFiniteElement/Instantiation/Spectral.hxx

...s/FiniteElement/RefFiniteElement/Private/BasicRefFElt.cpp

...teElement/RefFiniteElement/Private/RefFEltInFEltSpace.cpp

Sources/FormulationSolver/VariationalFormulation.hxx

Sources/Geometry/Coords.cpp

Sources/Geometry/Coords.hpp

Sources/Geometry/Coords.hxx

Sources/Geometry/Domain.cpp

Sources/Geometry/Domain.hpp