Log Message:
Update "mtr" package to version 0.74. Changes since version 0.72:
- KES reported a build problem. Turns out I need to install gtk-1.2
  on my development sytem, otherwise my release script causes the
  build to break.
- changed some docs to advertise the new mailing list.
- added documentation for the Mac OS X compilation problem.
- added -Wno-pointer-sign to the compiler options.
- Nico Lichtmaier's cleanup-gtk patch. (now mtr uses a more modern
  dialect of gtk).
- as possible after opening the sockets, it still had some
  sprintf calls, which have now been converted into snprintf.