pgsql: Support explicit placement of the temporary-table schema within

Log Message:
-----------
Support explicit placement of the temporary-table schema within search_path.
This is needed to allow a security-definer function to set a truly secure
value of search_path. Without it, a malicious user can use temporary objects
to execute code with the privileges of the security-definer function. Even
pushing the temp schema to the back of the search path is not quite good
enough, because a function or operator at the back of the path might still
capture control from one nearer the front due to having a more exact datatype
match. Hence, disable searching the temp schema altogether for functions and
operators.

Security: CVE-2007-2138

Tags:
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REL8_1_STABLE

Modified Files:
--------------
pgsql/doc/src/sgml/ref:
create_function.sgml (r1.67 -> r1.67.2.1)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/ref/create_function.sgml.diff?r1=1.67&r2=1.67.2.1)
pgsql/doc/src/sgml:
release.sgml (r1.400.2.41 -> r1.400.2.42)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/release.sgml.diff?r1=1.400.2.41&r2=1.400.2.42)
config.sgml (r1.36.2.7 -> r1.36.2.8)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/config.sgml.diff?r1=1.36.2.7&r2=1.36.2.8)
pgsql/src/backend/catalog:
aclchk.c (r1.120.2.1 -> r1.120.2.2)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/catalog/aclchk.c.diff?r1=1.120.2.1&r2=1.120.2.2)
namespace.c (r1.79.2.2 -> r1.79.2.3)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/catalog/namespace.c.diff?r1=1.79.2.2&r2=1.79.2.3)
pgsql/src/test/regress/expected:
temp.out (r1.10 -> r1.10.2.1)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/expected/temp.out.diff?r1=1.10&r2=1.10.2.1)
pgsql/src/test/regress/sql:
temp.sql (r1.6 -> r1.6.2.1)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/sql/temp.sql.diff?r1=1.6&r2=1.6.2.1)