SPELL and WEBSTER, again

["Leigh L. Klotz" <KLOTZ@AI.AI.MIT.EDU>]

C-M-$ on Twenex now uses the WEBSTER program instead of parsing the
database by itself.

The M-$ command on AI and OZ now uses an Fα algorithm for determining the
extent of the word.  Previously it used FW, but without preparing a ..D
syntax table.  This omission led to problems with apostrophe and hyphen in
some modes.  The Twenex spell program can understand apostrophe but not
hyphen, but the ITS version works with both.

WEBSTER has been changed to use the same algorithm in order
to be independent of the major mode and character syntax table.
The WEBSTER program on both Twenex and ITS works fine with apostrophe
and hyphen, so there's no problem there.

WEBSTER is currently a loadable library on AI (with no key assignments)
and autloaded on OZ via the SITE.INIT file.  I will make it be autoloaded
on AI as soon as I remember how; there's no SITE INIT file there.