RFR: JDK-8189611: JarFile versioned stream and real name support

[Xueming Shen]

Thanks Paul!

Webrev has been updated as suggested.

http://cr.openjdk.java.net/~sherman/8189611/webrev

jdeps' VersionHelper.java still accesses the "getRealName()" via the 
SharedSecrets.
Since jdeps is being compiled/built with the bootjdk, I'm leaving it 
untouched for
now.

----------------------
  610 // placeholder for now
  611 String getRealName(JarEntry entry) {
  612 return entry.getRealName();
  613 } No longer required?

  I dunno what calls it...
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sherman