pgsql: Add a couple of information functions to support direct checks on

Log Message:
-----------
Add a couple of information functions to support direct checks on whether
a schema is our own temp schema or another backend's temp schema, and use
these in place of some former kluges in information_schema.  Per my
proposal of yesterday.

Modified Files:
--------------
    pgsql/doc/src/sgml:
        func.sgml (r1.336 -> r1.337)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/func.sgml.diff?r1=1.336&r2=1.337)
    pgsql/src/backend/catalog:
        information_schema.sql (r1.36 -> r1.37)

(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/catalog/information_schema.sql.diff?r1=1.36&r2=1.37)
        namespace.c (r1.86 -> r1.87)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/catalog/namespace.c.diff?r1=1.86&r2=1.87)
    pgsql/src/include/catalog:
        catversion.h (r1.355 -> r1.356)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/catalog/catversion.h.diff?r1=1.355&r2=1.356)
        pg_proc.h (r1.423 -> r1.424)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/catalog/pg_proc.h.diff?r1=1.423&r2=1.424)