DERBY-532 Support deferrable constraints

Added an extra test case.

git-svn-id: https://svn.apache.org/repos/asf/db/derby/code/trunk@1577134 13f79535-47bb-0310-9956-ffa450edef68
DERBY-6507 Convert lang/fk_nonSPS.sql to JUnit ForeignKeysNonSpsTest

Patch derby-6707-2 which does the conversion.

git-svn-id: https://svn.apache.org/repos/asf/db/derby/code/trunk@1577135 13f79535-47bb-0310-9956-ffa450edef68