[tm-pubsubj] psdoc update - version 0.4

[Bernard Vatant <bernard.vatant@mondeca.com>]

Following recent proposals and exchange, I've released a new version of psdoc
http://www.oasis-open.org/committees/tm-pubsubj/docs/recommendations/psdoc.htm

The previous version is kept as "psdoc_03" as usual.

What's new?

-- Nothing in sections 1-3, except the introduction and use of "PS DocSet" for
abbreviation of Published Subjects Documentation Set, adopted throughout the document.

-- Split clearly the following into Requirements and Recommendations

Section 4 - "Requirements for PS DocSet Content"
Section 5 - "Recommended Syntaxes, and examples of PS DocSet"

The titles make it clear that the *content* is required, and various syntaxes only
recommended and illustrated by examples.
I think that is reflecting the best the consensus so-far.

-- Main new things are in section 4, some features needing discussion, and/or not
discussed so far

1. I've put in the Requirements part the notion that the PS DocSet shall be identified by
an URI, and that this URI shall be used as a namespace for PSIs inside the DocSet. (I
don't know if we should use "namespace" here, given the controversial status of that
word). This notion seemed implicit in the examples and discussion, and I found it an
easy-to-state and hopefully non too much controversial requirement.

2. I've proposed a "magical" (?) statement of purpose formal declaration.

3. The choice of mandatory PS DocSet metadata ... I think we'll fight on that with swords
and axes in Seattle :))

Bernard