DERBY-6617: Fix setting of permissions in MissingPermissionTest

- When forking a new JVM, pass on the properties that tell where
  various jar files are located.

- The specialized policy files for the test should include permissions
  required when running the test from Ant.

git-svn-id: https://svn.apache.org/repos/asf/db/derby/code/trunk@1610374 13f79535-47bb-0310-9956-ffa450edef68