Adapt all scripts called by JS to follow WSGI.

Move all Python scripts called by (AJAX) JavaScript ``philologic.js`` bodies,
previously inside a ``if __name__ == "__main__":``,
inside new functions with :data:`environ` and :data:`start_response` arguments,
allowing their calls by :func:`dispatcher`.
These functions no more print result on standart output, but instead, following WSGI,
initiate their HTTP responses with a call to :data:`start_response`, and return
their results (as HTTP responses bodies).
All these new functions are imported as is in their parent module.

Selection of which script should be executed is now set by new ``script`` CGI field.

Previous :data:`path_name` and :data:`db_path`, set in head of ``philologic.js``
are no more required, and replaced by new :data:`app_path`, which should point to
WSGI application URL.
Also, a new :data:`my_parentpath` variable is introduced, which should point to
parent location of ``philologic.js`` script, retrieved through script ``src`` attribute,
thanks to new id ``#philologicjs`` set to this node,
which allows call to ``ajax-loader.gif``.