Add support for Scilab language

by sploving for SWIG

This project adds the support for the Scilab language into SWIG. We will add a "-scilab" option to SWIG's current backend, which indicates SWIG to generate wrapper for Scilab. As the C++ language has not been fully supported by Scilab,we would implement the module with the C features. The project would make the function of SWIG more complete and the scilab language better flexibility. We will build the Scilab module based on the octave module which SWIG has supported already.