[MLton] htmldoc pdf MLton guide

[Stephen Weeks]

> One thing: at the moment, there are (web) links to the vewsvn.cgi
> stuff that point to the trunk.  That will be out of sync with what
> is in the release after a while.  I guess that the optimal would be
> for them to point to the repository version sync'd at the release.

That is easy.  I added a sed line to replace ViewSVN uses of "trunk"
with "tags/on-$version-release".  I made the change to grab-wiki
instead of make-pdf-guide, since the the same reasoning applies to the
links in the HTML docs.

There is one drawback of doing this, which is the links are broken
until the tag is created.  But it still seems like the way to go to
me.