RFR: 8042982: Unexpected RuntimeExceptions being thrown by SSLEngine

[Rob McKenna]

Hi folks,

A simple change to use SSLHandshakeException instead of RuntimeException 
in getAgreedSecret in DHCrypt and ECDHCrypt. This will prevent these 
RuntimeExceptions from propagating to the application and allow 
application programmers to handle them as SSLHandshakeExceptions.

http://cr.openjdk.java.net/~robm/8042982/webrev.01/

     -Rob