Changes to troffcvt distribution for release 1.04.

The most important changes are the addition of troff2html (a new
translator for converting troff to HTML), tblcvt (a preprocessor for
tbl input so that postprocessors can provide better tbl support) and
the implementation of a number of groff features.  See doc/groff.ms for
a list of groff features now supported by troffcvt.

Other changes are listed below:

- The distribution has been reorganized.  The major directories are:

	h		header files
	lib		general-purpose library and reader library stuff
	libunix		UNIX-specific library stuff
	libmac		Macintosh-specific library stuff
	troffcvt	source for troffcvt
	post		source for postprocessors
	doc		general documentation
	man		manual pages
	config		troffcvt-specific imake configuration files
	misc		other stuff

- 8-bit input characters (in the range 128-255) are allowed now.

- There is no longer a limitation of 255 special characters.

- Added -A option to troffcvt to suppress reading of default action file.

- Added -C option to troffcvt to enable compatibility mode (like -C in groff)

Incompatibilities:

Some options have changed:
- The troffcvt -nroff and -troff options are now specified using the -t
(formatter type) option as -t nroff and -t troff.
- The options for tc2text (and thus unroff), and tc2rtf (and thus troff2rtf)
have changed.

- Some internal names for special characters were changed.
For the most part, the new names match the PostScript names:

Old:			New:
@A-acute		@Aacute
@A-dieresis		@Adieresis
@A-grave		@Agrave
@E-acute		@Eacute
@E-dieresis		@Edieresis
@E-grave		@Egrave
@I-acute		@Iacute
@I-dieresis		@Idieresis
@I-grave		@Igrave
@O-acute		@Oacute
@O-dieresis		@Odieresis
@O-grave		@Ograve
@U-acute		@Uacute
@U-dieresis		@Udieresis
@U-grave		@Ugrave
@Y-acute		@Yacute
@Y-dieresis		@Ydieresis
@a-acute		@aacute
@a-dieresis		@adieresis
@a-grave		@agrave
@acute-accent		@acute
@approximately-equal	@approxequal
@approximates		@similar
@bell-system-logo	@bell
@bold-vertical		@bv
@box-vertical-rule	@br
@cap			@intersection
@cup			@union
@daggerdbl		@daggerdbl
@digit-space		@digitspace
@down-arrow		@arrowdown
@e-acute		@eacute
@e-dieresis		@edieresis
@e-grave		@egrave
@em-dash		@emdash
@empty-set		@emptyset
@footmark		@minute
@grave-accent		@grave
@greater-equal		@greaterequal
@hard-space		@hardspace
@i-acute		@iacute
@i-dieresis		@idieresis
@i-grave		@igrave
@identically-equal	@equivalence
@improper-subset	@reflexsubset
@improper-superset	@reflexsuperset
@ldblquote		@quotedblleft
@left-arrow		@arrowleft
@left-bottom-bracket	@braceleftbt
@left-ceiling-bracket	@bracketlefttp
@left-center-bracket	@braceleftmid
@left-floor-bracket	@bracketleftbt
@left-hand		@handleft
@left-top-bracket	@bracelefttp
@less-equal		@lessequal
@ligature-ff		@ff
@ligature-ffi		@ffi
@ligature-ffl		@ffl
@ligature-fi		@fi
@ligature-fl		@fl
@lsglquote		@quoteleft
@math-equals		@equalmath
@math-plus		@plusmath
@math-star		@asteriskmath
@member-of		@element
@n-tilde		@ntilde
@not			@logicalnot
@not-equal		@notequal
@o-acute		@oacute
@o-dieresis		@odieresis
@o-grave		@ograve
@o-slash		@oslash
@one-half		@onehalf
@one-quarter		@onequarter
@opt-hyphen		@opthyphen
@or			@bar
@partial-derivative	@partialdiff
@plus-minus		@plusminus
@rdblquote		@quotedblright
@right-arrow		@arrowright
@right-bottom-bracket	@bracerightbt
@right-ceiling-bracket	@bracketrighttp
@right-center-bracket	@bracerightmid
@right-floor-bracket	@bracketrightbt
@right-hand		@handright
@right-top-bracket	@bracerighttp
@root-extender		@radicalex
@rsglquote		@quoteright
@rule			@ru
@sixth-space		@sixthspace
@square-root		@radical
@subset			@propersubset
@superset		@propersuperset
@terminal-sigma		@sigma1
@three-fourths		@threequarters
@twelfth-space		@twelfthspace
@u-acute		@uacute
@u-dieresis		@udieresis
@u-grave		@ugrave
@underrule		@ul
@up-arrow		@arrowup
@y-acute		@yacute
@y-dieresis		@ydieresis
@zero-space		@zerospace
@field-begin		@fieldbegin
@field-end		@fieldend
@field-pad		@fieldpad