reset implementation

Hello

psycopg implements the connection.reset() method using the commands
RESET ALL and SET SESSION AUTHORIZATION DEFAULT.

Reading pgpool2 docs [1], I see that from PG 8.3 "DISCARD ALL" would
be more appropriate: it is equivalient to RESET ALL and SET SESSION
AUTHORIZATION DEFAULT plus more [2].

Ok to use DISCARD in reset() (on pg >= 8.3 only)?

[1] http://www.pgpool.net/docs/latest/doc/pgpool-en.html#RESET_QUERY_LIST
[2] http://www.postgresql.org/docs/current/static/sql-discard.html

-- Daniele