deadlock detection

My new code now checks for any type of non-escalation deadlock, even if
three or more processes have deadlocks where any two of them does not
represent a deadlock.

The one piece missing is to check for escalation deadlocks, where two
people get readlocks on the same table, and both then go for write-locks
on the same table.

--
Bruce Momjian maillist@candle.pha.pa.us