pgsql-server: ALTER TABLE SET TABLESPACE.

Log Message:
-----------
ALTER TABLE SET TABLESPACE. Gavin Sherry, some rework by Tom Lane.

Modified Files:
--------------
pgsql-server/doc/src/sgml/ref:
alter_table.sgml (r1.72 -> r1.73)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/doc/src/sgml/ref/alter_table.sgml.diff?r1=1.72&r2=1.73)
pgsql-server/src/backend/commands:
cluster.c (r1.126 -> r1.127)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/backend/commands/cluster.c.diff?r1=1.126&r2=1.127)
tablecmds.c (r1.118 -> r1.119)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/backend/commands/tablecmds.c.diff?r1=1.118&r2=1.119)
pgsql-server/src/backend/parser:
gram.y (r2.465 -> r2.466)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/backend/parser/gram.y.diff?r1=2.465&r2=2.466)
pgsql-server/src/include/commands:
cluster.h (r1.23 -> r1.24)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/include/commands/cluster.h.diff?r1=1.23&r2=1.24)
pgsql-server/src/include/nodes:
parsenodes.h (r1.260 -> r1.261)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/include/nodes/parsenodes.h.diff?r1=1.260&r2=1.261)