RFR 7095980: Ensure HttpURLConnection (and supporting APIs) don't expose HttpOnly cookies

[Chris Hegarty]

CR 7095980: Ensure HttpURLConnection (and supporting APIs) don't expose 
HttpOnly cookies

The changes use the internal/private java.net.HttpCookie parsing
implementation to filter out HttpOnly cookies from the Set-Cookie and
Set-Cookie2 headers returned in the HTTP protocol handler. With this
change I believe the HTTP protocol suitably protects HttpOnly cookies.

http://cr.openjdk.java.net/~chegar/7095980/webrev.00/webrev/

It reuses the internal java.net.HttpCookie parsing implementation rather 
than trying to maintain two separate parsing implementations. This is a 
little ugly since it is private and in the public java.net namespace, 
but I believe a shared secret is the best approach here. We could have 
moved the implementation itself into sun.net and just made it public, 
but I felt it cleaner to leave it as is.

Thanks,
-Chris.