java.security.cert.X509CRL: add new method verify(PublicKey, Provider)

New method introduced in Java 8. This method has a "default" implementation
in order to avoid breaking providers who construct concrete subclasses.

Unfortunately this implementation always results in an infinite loop, and
has thus been changed by an UnsupportedMethodOperation, with a TODO note
as to improve the situation if possible.

java/security/cert/X509CRL: add "default" method
sun/security/x509/X509CRLImpl: add declaration for that particular
implementation

Also, cosmetic changes like:
- use of @code tags instead of <code>
- use of static fields using the class name instead of instance name

This completes the port of this package to jdk8u60.

Bug: 29631070
Bug: 31294527
Test: make droid docs; old-cts run cts --class libcore.java.security.cert.X509CRLTest
Change-Id: Iccdfa3625a9ff2e7b808c22bce59ff75ae903e8a