Re-addd Rod's ALTER DOMAIN patch.

configure

doc/src/sgml/ref/alter_domain.sgml

doc/src/sgml/reference.sgml

src/backend/catalog/dependency.c

src/backend/catalog/pg_constraint.c

src/backend/catalog/pg_type.c

src/backend/commands/cluster.c

src/backend/commands/typecmds.c

src/backend/executor/execQual.c

src/backend/nodes/copyfuncs.c

src/backend/nodes/equalfuncs.c

src/backend/parser/gram.y

src/backend/parser/parse_expr.c

src/backend/tcop/postgres.c

src/backend/tcop/utility.c

src/include/catalog/pg_type.h

src/include/commands/defrem.h

src/include/commands/typecmds.h

src/include/nodes/nodes.h

src/include/nodes/parsenodes.h