RFR: JDK-8081814: Modularize the deploy build

[Erik Joelsson]

Hello,

Here is a review of the open changes needed for an Oracle internal 
change. The open changes should not affect the build but are mostly just 
providing more hooks for customizations or generalizing concepts. The 
changes have already been reviewed internally by Magnus Ihse and David 
DeHaven, but posting here for transparency and, of course, in case 
someone else have something to add.

Bug: https://bugs.openjdk.java.net/browse/JDK-8081814
Webrev: http://cr.openjdk.java.net/~erikj/8081814/webrev.01/

/Erik