RFR 8172975: SecurityTools.keytool() needs to accept user input

[Weijun Wang]

Please review the code changes at

    root: http://cr.openjdk.java.net/~weijun/8172975/root/webrev.00/
    jdk: http://cr.openjdk.java.net/~weijun/8172975/webrev.00/

The fix is in root repo. This is not an elegant solution because it uses 
a separate method to provide the response. This means you have to clear 
the response if the next keytool call does not need it. This also means 
you cannot run keytool in multiple threads.

I didn't provide the response as an extra argument because there are 
already many overloaded keytool() methods, and I do not want to invent a 
new method name (say, keytoolWithResponse) and implement the same number 
of overloaded methods.

If you are strongly against this solution, I'll think of another way.

The jdk change includes a test for this change, as well as a trivial fix 
for keytool's getYesNoReply() method. Otherwise an NPE is thrown with 
the following command:

    cat untrusted.cert | keytool -importcert -alias a

Thanks
Max