wiki20 update

[anita kean]

Hello

I've made some changes to the wiki20 documentation.
I'm attaching a diff of the wiki20 documentation,
as well as two other files:

1)wiki_external.py: a standalone script to run the
wiki20 model from the command-line

There's an
.. archive *****
line in the wiki20 docs (right at the end)
to place a link to this file
(Search on wiki_external.py)

2) a python shell/ ipython startup script
There's an
.. archive *****
line in the wiki20 docs (right at the end)
to place a link to this file
(Search on tg_shell_startup.py)

There is still some work to be done on the tutorial,
but it seems like I'm behind so I thought I should
submit it now.
I'd like to make some more changes and will
submit them by the end of the week.

--
Anita

[anita kean]

The diffs didn't pick up an extra file I use
in the docs - it's output of an ipython session
that is included in (end of the file).
Please find attached. For now it needs to be placed
in the same directory as the calling file wiki20.rst.

Apologies.
Anita