Replace comma overloading by dot function to denote scalar product

src/algebra/BiCGStab.hpp

src/algebra/CG.hpp

src/algebra/TinyVector.hpp

src/algebra/Vector.hpp

src/language/modules/MathModule.cpp

src/mesh/GmshReader.cpp

src/mesh/MeshData.hpp

src/mesh/MeshNodeBoundary.hpp

src/scheme/AcousticSolver.cpp

src/scheme/PerfectGas.cpp

tests/test_BiCGStab.cpp

tests/test_BuiltinFunctionProcessor.cpp

tests/test_CG.cpp

tests/test_LinearSolver.cpp

tests/test_MathModule.cpp

tests/test_TinyVector.cpp

tests/test_Vector.cpp