Proposal: #CustomizableAutomaticModuleNameMapping

[Mark Reinhold]

Issue summary
-------------

  #CustomizableAutomaticModuleNameMapping --- Provide a means to
  customize the algorithm that computes the names and version strings
  of automatic modules. [1]

Proposal
--------

Extend the `java.lang.module.ModuleDescriptor.Builder` API so that it
can be used to create automatic as well as explicit modules.  This will
allow a container application to use a custom `ModuleFinder` to manage
the mapping from artifact names to module names, version strings, and
so forth.


[1] http://openjdk.java.net/projects/jigsaw/spec/issues/#CustomizableAutomaticModuleNameMapping