pgsql: Add columns boot_val and reset_val to the pg_settings view, to

Log Message:
-----------
Add columns boot_val and reset_val to the pg_settings view, to expose
the value a parameter has at server start and will have after RESET,
respectively.

Greg Smith, with some modifications by me.

Modified Files:
--------------
pgsql/doc/src/sgml:
catalogs.sgml (r2.176 -> r2.177)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/catalogs.sgml?r1=2.176&r2=2.177)
pgsql/src/backend/utils/misc:
guc.c (r1.474 -> r1.475)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/misc/guc.c?r1=1.474&r2=1.475)
pgsql/src/include/catalog:
catversion.h (r1.493 -> r1.494)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/catalog/catversion.h?r1=1.493&r2=1.494)
pg_proc.h (r1.517 -> r1.518)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/catalog/pg_proc.h?r1=1.517&r2=1.518)
pgsql/src/test/regress/expected:
rules.out (r1.142 -> r1.143)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/expected/rules.out?r1=1.142&r2=1.143)