DERBY-6125 Code clean up in client driver.

Patch derby-6125-02-a. Removes the always false public static
Configuration#traceSuspended__ and its uses. It also removes a couple
of unused methods.

git-svn-id: https://svn.apache.org/repos/asf/db/derby/code/trunk@1462394 13f79535-47bb-0310-9956-ffa450edef68