RFR: JDK-8087208: Add devkit creation script for windows

[Erik Joelsson]

For reference, I would like to add the script used to create the devkit 
on Windows to the source tree.

Bug: https://bugs.openjdk.java.net/browse/JDK-8087208
Webrev: http://cr.openjdk.java.net/~erikj/8087208/webrev.01/

/Erik