RFR: JDK-8038500: (zipfs) Upgrade ZIP provider to be a supported provider

[Xueming Shen]

Hi,

Please help review this changeset to upgrade the zip filesystem provider 
implementation from
demo to a supported provider.

Back in JDK7 we created a demo file system provider for zip/jar files. 
It is shipped in two forms,
one as a binary under lib/ext that works "out of the box" to support 
zip/jar file access as a nio
filesystem, the second is source form with a BSD license.

We are now proposing to drop it as a demo and instead just "release" it 
as a filesystem provider
that shipped with the JDK.

issue: https://bugs.openjdk.java.net/browse/JDK-8038500
webrev: http://cr.openjdk.java.net/~sherman/8038500/webrev

Thanks!
-Sherman