pgsql: Add a RESTART (without parameter) option to ALTER SEQUENCE,

Log Message:
-----------
Add a RESTART (without parameter) option to ALTER SEQUENCE, allowing a
sequence to be reset to its original starting value. This requires adding the
original start value to the set of parameters (columns) of a sequence object,
which is a user-visible change with potential compatibility implications;
it also forces initdb.

Also add hopefully-SQL-compatible RESTART/CONTINUE IDENTITY options to
TRUNCATE TABLE. RESTART IDENTITY executes ALTER SEQUENCE RESTART for all
sequences "owned by" any of the truncated relations. CONTINUE IDENTITY is
a no-op option.

Zoltan Boszormenyi

Modified Files:
--------------
pgsql/doc/src/sgml/ref:
alter_sequence.sgml (r1.19 -> r1.20)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/ref/alter_sequence.sgml?r1=1.19&r2=1.20)
truncate.sgml (r1.25 -> r1.26)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/ref/truncate.sgml?r1=1.25&r2=1.26)
pgsql/src/backend/catalog:
pg_depend.c (r1.27 -> r1.28)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/catalog/pg_depend.c?r1=1.27&r2=1.28)
pgsql/src/backend/commands:
sequence.c (r1.150 -> r1.151)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/commands/sequence.c?r1=1.150&r2=1.151)
tablecmds.c (r1.253 -> r1.254)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/commands/tablecmds.c?r1=1.253&r2=1.254)
pgsql/src/backend/nodes:
copyfuncs.c (r1.393 -> r1.394)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/nodes/copyfuncs.c?r1=1.393&r2=1.394)
equalfuncs.c (r1.322 -> r1.323)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/nodes/equalfuncs.c?r1=1.322&r2=1.323)
pgsql/src/backend/parser:
gram.y (r2.614 -> r2.615)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/parser/gram.y?r1=2.614&r2=2.615)
keywords.c (r1.195 -> r1.196)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/parser/keywords.c?r1=1.195&r2=1.196)
pgsql/src/bin/pg_dump:
pg_dump.c (r1.491 -> r1.492)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/bin/pg_dump/pg_dump.c?r1=1.491&r2=1.492)
pgsql/src/include/catalog:
catversion.h (r1.460 -> r1.461)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/catalog/catversion.h?r1=1.460&r2=1.461)
dependency.h (r1.34 -> r1.35)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/catalog/dependency.h?r1=1.34&r2=1.35)
pgsql/src/include/commands:
sequence.h (r1.40 -> r1.41)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/commands/sequence.h?r1=1.40&r2=1.41)
pgsql/src/include/nodes:
parsenodes.h (r1.365 -> r1.366)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/nodes/parsenodes.h?r1=1.365&r2=1.366)
pgsql/src/test/regress/expected:
sequence.out (r1.9 -> r1.10)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/expected/sequence.out?r1=1.9&r2=1.10)
truncate.out (r1.13 -> r1.14)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/expected/truncate.out?r1=1.13&r2=1.14)
pgsql/src/test/regress/sql:
sequence.sql (r1.4 -> r1.5)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/sql/sequence.sql?r1=1.4&r2=1.5)
truncate.sql (r1.6 -> r1.7)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/sql/truncate.sql?r1=1.6&r2=1.7)