Modular JAR file support

[Alan Bateman]

Mandy Chung wrote:
>
> :
>
> Webrev at:
>     http://cr.openjdk.java.net/~mchung/jigsaw/webrevs/modular-jar-file/
I went through the webrev and the changes mostly look good to me, easy 
to follow. A general comment is that the install is open to races with 
other concurrent access to the module library but that's a bigger 
problem, not a big concern for this.

I read the mail from David Schlosnagle on the missing close and a 
related suggestion for using try-with-resources is that 
ModuleFileFormat.Reader could implement Closeable which would allow a 
bit of clean-up in SimpleLibrary.install.

Minor nit, the copyright year on the test in 2009.

-Alan.