Removed trailing whitespace from all .sml and .sig files.

This affects over 900 files and was done using emacs's delete-trailing-whitespace
function in batch mode. Building the system with Poly/ML and Moscow ML seems to
work, so I'm hoping these changes don't break anything. Please complain if
they do!

Version 1.2: 19 November 2002

Goals submitted to MESON_TAC when HOL is built .......... 1779
Proved by MESON_TAC ..................................... 1779
Proved by METIS_TAC within 10s .......................... 1774

Between Versions 1.1 and 1.2

* Ground-up reimplementation of the resolution calculus, which now
performs ordered resolution and ordered paramodulation.
* A single entry-point METIS_TAC, which uses heuristics to decide
whether to apply FO_METIS_TAC or HO_METIS_TAC.
* {HO|FO}_METIS_TAC both initially operate in typeless mode, and
automatically try again with types if an error occurs during proof
translation.
* Extensionality axiom now included in HO_METIS_TAC by default.

Initial check-in of the Metis first-order prover.