RFR 8194260, Point-to-point interface should be excluded from java/net/ipv6tests/*

[Felix Yang]

Hi all,

    please review the following patch to apply NetworkConfiguration 
library to exclude point-to-point interfaces.

Bug:

     https://bugs.openjdk.java.net/browse/JDK-8194260

Webrev:

     http://cr.openjdk.java.net/~xiaofeya/8194260/webrev.00/

Thanks,

Felix