follows recent pghackers discussion.  This commit includes all the
relevant fixes from Greg Mullane's patch of 24-June.

about TO/FROM direction in several places.

I concluded that RENAME should require CREATE privilege on the namespace
as well as ownership of the table.

different privilege bits (might as well make use of the space we were
wasting on padding).  EXECUTE and USAGE bits for procedures, languages
now are separate privileges instead of being overlaid on SELECT.  Add
privileges for namespaces and databases.  The GRANT and REVOKE commands
work for these object types, but we don't actually enforce the privileges
yet...

 between Postgres and PostgreSQL.

and REVOKE FROM PUBLIC: the latter is not the same as 'revoke from all
users', but the ref page blurred the difference.

Place it in the expected place in the User's Guide, rather than
hiding it in the command reference page for CREATE SEQUENCE.

for GRANT/REVOKE is now just that, not "CHANGE".

On the way, migrate some of the aclitem internal representation away from
the parser and build a real parse tree instead.  Also add some 'const'
qualifiers.

privileges.  INSERT and COPY FROM now require INSERT (only).  Add
privileges regression test.

Fix misspelling of disbursion to dispersion.

ecpg reference page still needs formatting.

No big deal; fixed lots of other markup at the same time.
Bigest change: make sure there is no whitespace
 in front of <term> contents.
This will probably help the other output types too.

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