pgsql: Add ALTER VIEW ...

Log Message:
-----------
Add ALTER VIEW ... RENAME TO, and a RENAME TO clause to ALTER SEQUENCE.
Sequences and views could previously be renamed using ALTER TABLE, but
this was a repeated source of confusion for users. Update the docs,
and psql tab completion. Patch from David Fetter; various minor fixes
by myself.

Modified Files:
--------------
pgsql/doc/src/sgml:
reference.sgml (r1.63 -> r1.64)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/reference.sgml.diff?r1=1.63&r2=1.64)
pgsql/doc/src/sgml/ref:
allfiles.sgml (r1.70 -> r1.71)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/ref/allfiles.sgml.diff?r1=1.70&r2=1.71)
alter_sequence.sgml (r1.16 -> r1.17)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/ref/alter_sequence.sgml.diff?r1=1.16&r2=1.17)
create_view.sgml (r1.35 -> r1.36)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/ref/create_view.sgml.diff?r1=1.35&r2=1.36)
drop_view.sgml (r1.23 -> r1.24)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/ref/drop_view.sgml.diff?r1=1.23&r2=1.24)
pgsql/src/backend/commands:
alter.c (r1.23 -> r1.24)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/commands/alter.c.diff?r1=1.23&r2=1.24)
tablecmds.c (r1.228 -> r1.229)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/commands/tablecmds.c.diff?r1=1.228&r2=1.229)
pgsql/src/backend/parser:
gram.y (r2.596 -> r2.597)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/parser/gram.y.diff?r1=2.596&r2=2.597)
pgsql/src/backend/tcop:
utility.c (r1.282 -> r1.283)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/tcop/utility.c.diff?r1=1.282&r2=1.283)
pgsql/src/bin/psql:
tab-complete.c (r1.165 -> r1.166)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/bin/psql/tab-complete.c.diff?r1=1.165&r2=1.166)
pgsql/src/include/commands:
tablecmds.h (r1.33 -> r1.34)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/commands/tablecmds.h.diff?r1=1.33&r2=1.34)

Added Files:
-----------
pgsql/doc/src/sgml/ref:
alter_view.sgml (r1.1)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/ref/alter_view.sgml?rev=1.1&content-type=text/x-cvsweb-markup)