Update to JEP 261: Module System

[mark.reinhold at oracle.com]

I've updated JEP 261 (http://openjdk.java.net/jeps/261).  Major changes
include:

  - The special ALL-DEFAULT module name, which represents the default
    set of root modules for use with the -addmods option [1];

  - A more thorough explanation of how the built-in class loaders have
    changed, how built-in modules are assigned to each loader, and how
    these loaders work together to load classes [2]; and

  - The reason why Java EE-related modules are no longer resolved by
    default [3].

There are various other minor corrections and clarifications, as can be
seen in the detailed diff [4].

- Mark


[1] http://openjdk.java.net/jeps/261#ALL-DEFAULT
[2] http://openjdk.java.net/jeps/261#Class-loaders
[3] http://openjdk.java.net/jeps/261#EE-modules
[4] http://cr.openjdk.java.net/~mr/jigsaw/jeps/updates/261-2016-06-15.html