[ssax-sxml] New edition of SXML

[<ol...@po...>]

Hello!

	I have committed a draft version of edition 2.1 of SXML for
your comments.

	SSAX/docs/SXML.scm       -- the master file
	SSAX/docs/SXML.html      -- HTML form
	SSAX/docs/SXML-paper.tex -- LaTeX form
	SSAX/docs/SXML-paper.scm -- a stylesheet for the latter

You can browse these documents as
	http://cvs.sourceforge.net/cgi-bin/viewcvs.cgi/ssax/SSAX/docs/
or download them by doing "cvs update".

	The major changes are stylistic ones. The new document
hopefully explains the treatment of namespaces better. To avoid
confusion, we rename 'user-ns-prefix' into 'user-ns-shortcut' and
introduce a non-terminal 'namespace-id'. The document explains how the
latter differs from XML namespace prefixes.  The SXML grammar is also
given in a more precise (and also in a more abstract, see SXML.scm)
way.

	Kirill has noticed that several references to the XML Infoset
Recommendation are no longer valid because of the changes made to the
Infoset Recommendation. The draft SXML document fixes that. Kirill has
suggested a new SXML node '@@' as a container for future
extensions. It is this addition that prompted the increase in the
edition version number.

	Kirill has also suggested to make the notation for service
symbols more uniform. SSAX already employs the character '@' (to mark the
attribute collection and, as @@, to mark the extension collection). It
may make sense therefore to replace
	*TOP*  -> @TOP@
	*PI*   -> @PI@
	*COMMENT* -> @COMMENT@
	*ENTITY*  -> @ENTITY@
	*NAMESPACES* -> @NAMESPACES@

Nodes such as *PI* are not used often; still the changes may break
some code. SSAX.scm has to be modified as well. Nevertheless, if the
change seems desirable, it's better to make it sooner than
later. Comments?

	Cheers,
	Oleg