Unicode sequences, @typeface, and the font/typeface distinction

A run of Unicode code points now needs one pair of carets, not one pair
each: ^9053 53EF 9053^ renders the characters adjacently, and a single
character inside such a run stands for itself.  An invalid code point is
an error naming the position that wrote it, rather than an apology
rendered into the finished document; noncharacters are refused alongside
surrogates; and a code point that lands on a Klammertext special is safe
through the re-reads that assemble a document.  The character tables now
produce the precomposed form, so a diacritic written as ^a" and one typed
directly are the same text to a search or a copy-paste.

"kdesc -u" describes how to write a Unicode character, with tables of
glyphs beside the codes that produce them.  It is new and not yet
complete: it predates the sequence form and the typeface klammer below.

A typeface and a style are no longer both called "font".  A typeface is a
family resolved by name; a style code is the one letter naming a type
style.  So @document takes :serif_typeface and its siblings, a table takes
:style, captions take :caption_style and :caption_size, the uniform scale
is :text_scale, and the command is "kdesc --typeface".  This renames
arguments a document may already use; an old name is a located error
rather than a silent omission.

@typeface sets a passage in another typeface for the length of that
passage:

    @typeface Noto Sans Egyptian Hieroglyphs | ^132AA 133CF^ :scale 1.5 @

Writing the klammer is the whole declaration -- the document resolves the
typeface, embeds it in what it produces, and carries its license along.
Two typefaces for scripts no text font covers now ship with Klammertext:
Noto Sans Egyptian Hieroglyphs and Noto Sans Cuneiform.  Every typeface in
the distribution now carries its license file.

(from dev 61e598698891)

sks/list/list.py

@@ -66,7 +66,7 @@ class Define(klammer_base.Klammer_base):
                     "b" : f"<b>{s}</b>",
                     "t" : f'<span class="monospace">{s}</span>',
                     "c" : f'<span class="monospace">{s}</span>',
-                    "s" : f'<span class="sansserif">{s}</span>'}[self.font]
+                    "s" : f'<span class="sansserif">{s}</span>'}[self.style]
         result = "\n\n".join([f"<dt>{fontify(term)}</dt>\n<dd>{definition}</dd>"
                               for term,definition in self.items])
         result = f"<dl>\n{result}\n</dl>"
@@ -79,7 +79,7 @@ class Define(klammer_base.Klammer_base):
                     'b' : r'\normalfont\bfseries',
                     't' : r'\normalfont\ttfamily',
                     'c' : r'\normalfont\ttfamily',
-                    's' : r'\normalfont\sffamily'}[self.font]
+                    's' : r'\normalfont\sffamily'}[self.style]
             return f"{font} {s}"
         # The "\hfill\newline" was to force the description to the next line even if the item was small:
         # result = "\n\n".join([f"\\item[{{{fontify(term)}}}]\\hfill\n\\newline {definition}"