DERBY-6610: suites.All cannot be run with classes without failures

Grant the derbyTesting.codeclasses code base permission to access
temporary files to allow DatabaseClassLoadingTest and
NativeAuthenticationServiceTest to run with classes.

git-svn-id: https://svn.apache.org/repos/asf/db/derby/code/trunk@1602102 13f79535-47bb-0310-9956-ffa450edef68