string api

[Roman Hunt]

hello:
        I am interested in contributing to the project.  (Thank Dan's
        cross-country tour :)  This is my first project of this size
        and importance, but I feel up to the task.  (Read: "Please, be
        patient with the newbie").  I have begun work on
        string_nprintf() as strings.pod says that it was still
        unimplemented. I have run into a few questions though: I can't
        find the definition for the string_vtable it is not in
        string.h as the pod states.  Also, what would be the standard
        way to map a C string into a STRING would one just call
        string_make passing a pointer to the char buffer  with
        the correct encoding passed in, and the strings length into
        len?