pgsql-server: Remove TABLESPACE option of CREATE SEQUENCE; sequences

Log Message:
-----------
Remove TABLESPACE option of CREATE SEQUENCE; sequences will now always
live in database or schema's default tablespace, as per today's discussion.
Also, remove some unused keywords from the grammar (PATH, PENDANT,
VERSION), and fix ALSO, which was added as a keyword but not added
to the keyword classification lists, thus making it worse-than-reserved.

Modified Files:
--------------
    pgsql-server/doc/src/sgml/ref:
        create_sequence.sgml (r1.40 -> r1.41)

(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/doc/src/sgml/ref/create_sequence.sgml.diff?r1=1.40&r2=1.41)
    pgsql-server/src/backend/commands:
        sequence.c (r1.112 -> r1.113)

(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/backend/commands/sequence.c.diff?r1=1.112&r2=1.113)
    pgsql-server/src/backend/nodes:
        copyfuncs.c (r1.287 -> r1.288)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/backend/nodes/copyfuncs.c.diff?r1=1.287&r2=1.288)
        equalfuncs.c (r1.226 -> r1.227)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/backend/nodes/equalfuncs.c.diff?r1=1.226&r2=1.227)
    pgsql-server/src/backend/parser:
        analyze.c (r1.306 -> r1.307)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/backend/parser/analyze.c.diff?r1=1.306&r2=1.307)
        gram.y (r2.466 -> r2.467)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/backend/parser/gram.y.diff?r1=2.466&r2=2.467)
        keywords.c (r1.150 -> r1.151)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/backend/parser/keywords.c.diff?r1=1.150&r2=1.151)
    pgsql-server/src/bin/pg_dump:
        pg_dump.c (r1.377 -> r1.378)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/bin/pg_dump/pg_dump.c.diff?r1=1.377&r2=1.378)
    pgsql-server/src/include/nodes:
        parsenodes.h (r1.261 -> r1.262)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/include/nodes/parsenodes.h.diff?r1=1.261&r2=1.262)