8174823: Module system implementation refresh (3/2017)

[Alan Bateman]

We have been accumulating changes in the jake forest for the last few 
weeks to align with the proposals in JSR 376 and also to pick up API 
changes and bug fixes. It's time to bring these changes into jdk9/dev. 
The issue to bring these changes into jdk9/dev in bulk has been approved 
via the FC extension process (still in use during JDK 9 RDP2).

A summary of the main changes is listed in JDK-8174823 [1], and the 
webrevs with the changes to bring to jdk9/dev are here:
    http://cr.openjdk.java.net/~alanb/8174823/1/

The changes are currently based on jdk-9+161 and will be rebased before 
pushing.

-Alan

[1] https://bugs.openjdk.java.net/browse/JDK-8174823