Revert "Fix for PostgreSQL error on Mac OS X"

This reverts commit 82d732a3d61cc2fa46a606181891eddf4797beb6. That patch
caused problems, as we depend on the PostgreSQL error codes in some of
our apps. pg_result_error_field() which we use to retrieve the error code
does not work with pg_query() as opposed to pg_send_query() -- see
http://no2.php.net/pg_result_error_field.

We need to come up with a proper fix for "Cannot set connection to
blocking mode" on Mac OS X. Some suggestions and a good explanation for
the error is here:
http://stackoverflow.com/questions/865017/pg-send-query-cannot-set-connection-to-blocking-mode