RFR JDK-8131067: (zipfs) Zip File System Provider returns doubly-encoded Path URIsRFR

[Xueming Shen]

Hi

Please hep review the change for  JDK-8131067.

Issue: https://bugs.openjdk.java.net/browse/JDK-8131067
webrev: http://cr.openjdk.java.net/~sherman/8131067

It appears URI constructor URI(scheme, ssp, fragment) quotes
any 'non-legal-uri-character". Need to decode the uri string from
path before passing into URI constructor to create a new one.
The "decode" is a copy/paste from the j.net.URI class with some
optimization.

Thanks,
Sherman