DERBY-6628 Intermittent error in TriggerGeneralTest

Patch derby-6628-more-diagnostics: a diagnostics patch that will dump
the entire lock table in if we see the unexpected set of locks seen in
this issue.

git-svn-id: https://svn.apache.org/repos/asf/db/derby/code/trunk@1606723 13f79535-47bb-0310-9956-ffa450edef68