FRF[14] JDK-8228967: Trust/Key store and SSL context utilities for tests

[sha.jiang at oracle.com]

Hi,
This enhancement provides a set of utilities for creating certificate, 
trust/key store and SSL context.
It provides the default trust and key stores with RSA, ECDSA, RSASSA-PSS 
and DSA certificates, and also the default TLS and DTLS contexts with 
the default trust and key stores.
Three tests are modified for demonstrating the usages.

Webrev: http://cr.openjdk.java.net/~jjiang/8228967/webrev.00/
Issue: https://bugs.openjdk.java.net/browse/JDK-8228967

Best regards,
John Jiang