RFR: JDK-8065183: Add --with-copyright-year option to configure

[Erik Joelsson]

Hello,

Please review this small change, adding a configure option for changing 
the COPYRIGHT_YEAR value.

Bug: https://bugs.openjdk.java.net/browse/JDK-8065183
Webrev: http://cr.openjdk.java.net/~erikj/8065183/webrev.root.01/

The same patch applies cleanly to jdk8u, except for generated-configure 
of course, and I would like to backport this to 8u.

/Erik