Add documentation for the fallback director.
Rewrite first paragraph to make it easier to read.
Add dependeny to build both rst files from vcc.

Fix spotty dependency where none or just one of the
.rst files output by vmodtool.py was known by the Makefile.
Tiny lint; file is called vmod.vcc.
Output correct tool name.

And avoid hardcoding it, in case we change it in the future
some time.
Output autogen-msg to .rst; pythonify a bit.

Write a header in generated .rst files that it was generated from the
.vcc file.

Also softly sprinkled with some python formatting:
* use a python 2.5 context manager for the filepointer
* and make the output easier to read by avoiding concatination.
Remove text block dividers just added.

This made it easier to see where objects started/stopped, but
vmodtool.py don't believe in this comment format. Especially rst2man
wasn't impressed, so roll back for now.