Backpatch certain files through 9.1

Backpatch certain files through 9.0

Update all files in head, and files COPYRIGHT and legal.sgml in all back
branches.

Fully update git head, and update back branches in ./COPYRIGHT and
legal.sgml files.

pointed out by Stefan Kaltenbrunner

back-stamped for this.

Tag appropriate files for rc3

Also performed an initial run through of upgrading our Copyright date to
extend to 2005 ... first run here was very simple ... change everything
where: grep 1996-2004 && the word 'Copyright' ... scanned through the
generated list with 'less' first, and after, to make sure that I only
picked up the right entries ...

to RELEASE_CHANGES so that this is not forgotten in the future.

$Header: -> $PostgreSQL Changes ...

vague cross-references with real links.

Fix up references to "PostgreSQL" rather than "Postgres". Was roughly
 evenly split between the two before. ref/ files not yet done.

General cleanup for 7.0.

regression tests so I prepared a set of expected
files to make things look OK.

There's also a file to account for minor variations
in the geopmetry output and a resultmap patch to
pull them all together.

With these changes PostgreSQL, from CVS, builds and
regression tests (runcheck) cleanly.

Keith Parks.

A few other changes, but I forget what :(

Add id tags to chapter and section headings to ensure good labels
 on output html files.

Clean out duplicate stuff in odbc.sgml resulting from a faulty patch.

 of Norm's Modular Style Sheets and jade/docbook.
From Vince Vielhaber <vev@michvhf.com>.

Split introduction sections into separate files to allow the legal notice
 and notation sections appear in all documents without having the history
 show up everplace too.
Add full list of reserved and non-reserved key words in syntax.sgml.
Add a separate chapter to the admin guide on security.