pgsql: Mmark client-side prepare/bind/execute statements with "[client]"

Log Message:
-----------
Mmark client-side prepare/bind/execute statements with "[client]" so
they can be easily distinguished from SQL commands.

Modified Files:
--------------
pgsql/src/backend/tcop:
postgres.c (r1.471 -> r1.472)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/tcop/postgres.c.diff?r1=1.471&r2=1.472)