Initial version of the SQL information schema

doc/src/sgml/features.sgml

doc/src/sgml/release.sgml

src/backend/Makefile

src/backend/catalog/Makefile

src/backend/catalog/information_schema.sql

src/bin/initdb/initdb.sh

src/test/regress/expected/rules.out

src/test/regress/expected/type_sanity.out

src/test/regress/input/create_function_2.source

src/test/regress/output/create_function_2.source

src/test/regress/sql/rules.sql

src/test/regress/sql/type_sanity.sql