Log Message:
Update mimetex to 0.70.

* 6 Sep 2008 -- An image like XXX doesn't look as good as the same image XXX
  that's vertically aligned with your surrounding text. Along with several
  standard HTTP header fields, mimeTeX now also emits a special
  Vertical-Align: -nn   header, where -nn is the number of pixels (usually
  negative as illustrated) needed for a   style="Vertical-Align: -nn px"
  attribute in the <img> tag used to render your expression.
  See the mimeTeX manual for further discussion.
* 5 Sep 2008 -- Users running mimeTeX as a Win32 DLL with Shital Shah's Code
  Project reported that color directives aren't reset, e.g., an expression
  containing \red is rendered red as directed, but all subsequent images are
  red, too.
  This has been fixed (along with several similar bugs nobody noticed).
  It never affected users running mimeTeX in the usual way, as a cgi.