[This is a repost - it supercedes the previous one. It fixes the patch so
it doesn't bread aix port, plus there's a file missing out of the
original post because difforig doesn't pick up new files. It's now
attached. peter]

This patch brings the JDBC driver up to the current protocol spec.
Basically, the backend now tells the driver what authentication scheme to
use.

The patch also fixes a performance problem with large objects. In the
buffer manager, each fastpath call was sending multiple Notifications to
the backend (sometimes more data in the form of notifications were being
sent than blob data!).