mimics matlab function str2mat
m=str2mat(arg1,...,argn)
* argi = a string or a vector of strings
* m = a (px1) vector of strings
str2mat(['a1' 'a2'],'b1',['c1';'c2';'c3']) // returns: // ans = //!a1 ! //! ! //!a2 ! //! ! //!b1 ! //! ! //!c1 ! //! ! //!c2 ! //! ! //!c3 !