RFR JDK-8200172,String.split non-positive term incorrect use

[Xueming Shen]

Hi,

Please help review a api doc clarification for 
String.split()/Pattern.split().

issue: https://bugs.openjdk.java.net/browse/JDK-8200172
webrev: http://cr.openjdk.java.net/~sherman/8200172/webrev

As suggested, it appears to be clear, straightforward and less confusion 
to simply
categorize the clauses as "if positive", "if negative" and "if zero".

It's simply a rewording to clear things up, I would assume csr is not 
necessary here.

thanks,
Sherman