Add UNICODE_CHARACTER_CLASS flag to Regex flag parsing

[bleskes]

Hi,

Java's Regex have issue with character classes when it comes to unicode content (
http://stackoverflow.com/questions/4304928/unicode-equivalents-for-w-and-b-in-java-regular-expressions
)

Apparently they solved things in Java7 by adding a special flag: UNICODE_CHARACTER_CLASS ( http://docs.oracle.com/javase/7/docs/api/java/util/regex/Pattern.html#UNICODE_CHARACTER_CLASS )

Sadly org.elasticsearch.common.regex doesn't "understand" it. As Java7 is the recommended runtime for ES I think it's OK to add it even if not supported by earlier JDK.

Cheers,
Boaz

[s1monw]

yeah makes sense... I will add it in a bit