Updates to fix most warnings on cx1.

CMakeLists.txt

cmake/Nektar++Config.cmake.in

cmake/NektarCommon.cmake

cmake/ThirdPartyBoost.cmake

cmake/ThirdPartyLoki.cmake

cmake/ThirdPartyTinyxml.cmake

library/LibUtilities/BasicUtils/SessionReader.h

library/LibUtilities/LinearAlgebra/NekVector.cpp

library/LibUtilities/LinearAlgebra/NekVector.hpp

library/MultiRegions/AssemblyMap/AssemblyMap.cpp

library/MultiRegions/AssemblyMap/AssemblyMap.h

library/MultiRegions/AssemblyMap/AssemblyMapCG.cpp

library/MultiRegions/AssemblyMap/AssemblyMapCG.h

library/MultiRegions/AssemblyMap/AssemblyMapDG.cpp

library/MultiRegions/AssemblyMap/AssemblyMapDG.h

library/MultiRegions/ContField2D.h

library/MultiRegions/ExpList.h

library/MultiRegions/GlobalLinSysDirectStaticCond.cpp

library/MultiRegions/GlobalLinSysIterative.cpp

library/MultiRegions/GlobalLinSysIterativeFull.cpp