Add a simple `zero-context' disambiguation script.

        The disambiguation work is still in progress. However, there
        is a relatively stable/usable disambiguation method that does
        not make any use of the context. This change adds a python
        script that only does disambiguation (no training option yet).
        An external model file is required, which can be obtained at
        the URL http://www.let.rug.nl/~coltekin/trmorph/1M.m2.