Survex 1.0.18 released

[Olly Betts]

Oops, I actually uploaded this several days ago, but forgot to send out
an announcement!

http://www.survex.com/download.html

No versions for RISC OS or MSDOS on 286 or earlier machines this time.
Nothing relevant to them has changed since 1.0.14.

In fact this is really only relevant to Unix users, unless you're
interested in the 3d file format:

Here's the usual summary of changes in 1.0.18:

* (Unix Version): Fixed "Process" action on .svx files.

* (Unix Version): File associations: if svxedit isn't installed, run gnome-edit
  instead.

* (Unix Version): In Debian packages, now include file associations and file
  icons in the survex package rather than survex-aven.

* (Unix Version): File associations were missing from RPM packages; moved
  aven and svxedit man pages to their respective subpackages; moved aven icons
  to the aven subpackage.

* Documentation: added details of the 3d file format (version 3).

* Updated TODO list.

Cheers,
Olly