RFR JDK-8147531,To add named character construct \N{...} to support Unicode name property

[Xueming Shen]

Hi,

Please help review the change to add \N support in regex.

Issue: https://bugs.openjdk.java.net/browse/JDK-8147531
webrev: http://cr.openjdk.java.net/~sherman/8147531/webrev

This is one of the items we were planning to address via JEP111
http://openjdk.java.net/jeps/111
https://bugs.openjdk.java.net/browse/JDK-8046101

Some of the constructs had been added already in early release. I'm
planning to address the rest as individual rfe separately.

Thanks,
Sherman