Add function: SymbolicMatrixMatlab diag(const SymbolicMatrixMatlab& a) in Symbolic MatrixMatlabHelper.hpp
Add diag and elementwiseProd operation to SymbolicMatrixAdaptor.hpp
Add diagOp and MMFunc diag to MatrixMatrixFuncHelper.hpp
Add elementwise to MMFunc. Need debug and test. Use % instead of .* for elementwise operation in the program.