Code review needed for 6737819

[Jean-Christophe Collet]

Here are the changes for 6737819.
This allows for the previously hard-coded, always in, values for 
http.nonProxyHosts and ftp.nonProxyHosts to be overridden when necessary.
I.E. before it was never possible to reach localhost (and its 
variations) via a proxy (hard coded exemption). These changes keep that 
behavior by default, but make it possible to change it.

http://cr.openjdk.java.net/~jccollet/6737819/webrev.00/