[9] RFR: 7194452: Remove "Reverse" PKIX CertPathBuilder implementation

[Jason Uh]

Please review this change to remove the "Reverse" CertPathBuilder mode, 
which has never been supported and is undocumented.

webrev: http://cr.openjdk.java.net/~juh/7194452/00/
bug: https://bugs.openjdk.java.net/browse/JDK-7194452
Thanks,
Jason