DERBY-6623 DatabaseMetaDataTest fails intermittently

Patch derby-6623 introduced JDBC#assertunorderedResultSet to solve the
issue. It also cleans up a number of IDE warnings (missing Javadocs,
old style loop code, variable shadowing).

git-svn-id: https://svn.apache.org/repos/asf/db/derby/code/trunk@1603944 13f79535-47bb-0310-9956-ffa450edef68