Code cleanup for password storage schemes.
Used AutoRefactor.
Reduced variable scopes.


PBKDF2PasswordStorageScheme.java:
Extracted methods getDigestBytes(), encodeAndMatch(),
Removed unnecessary use of StringBuilders.
In passwordMatches() and authPasswordMatches(), used String.indexOf().

PKCS5S2PasswordStorageScheme.java:
See general changes.

PKCS5S2PasswordStorageSchemeTestCase.java:
In getTestPasswords(), reused the super method and filtered entries.
Fix test failures with Java 6 due to limitation in JDK.