Better HTML chars -- – and —.
 [jmk] --rwxrwxr-x M 137273 glenda sys 160723 Sep 21 23:43 386/bin/htmlfmt
	/sys/src/libhtml/lex.c:Tconv
	/sys/src/libhtml/lex.c:_gettoks
	/sys/src/libhtml/lex.c:ampersand
	/sys/src/libhtml/lex.c:backup
	/sys/src/libhtml/lex.c:comment
	/sys/src/libhtml/lex.c:getchar
	/sys/src/libhtml/lex.c:getdata
	/sys/src/libhtml/lex.c:gettag
	/sys/src/libhtml/lex.c:newtokensource
 [jmk] --rw-rw-r-- M 137273 glenda sys 220134 Sep 21 23:43 386/lib/libhtml.a