DERBY-6370: dblook doesn't schema-qualify identifiers in trigger actions

Rewrite the triggered SQL statement and the WHEN clause of a trigger
so that all identifiers are fully qualified, before they are stored in
SYS.SYSTRIGGERS and SYS.SYSSTATEMENTS. This way, dblook is able to use
the information in the system tables to produce DDL that is
independent of the schema in which it is executed.

git-svn-id: https://svn.apache.org/repos/asf/db/derby/code/trunk@1591216 13f79535-47bb-0310-9956-ffa450edef68