RFR (S): 8238220: Rename OWSTTaskTerminator to TaskTerminator

[Thomas Schatzl]

Hi all,

   can I have reviews for this renaming change of OWSTTaskTerminator to 
TaskTerminator now that there is only one task termination protocol 
implementation?

I believe that the OWST prefix only makes the code harder to read 
without conveying interesting information at the uses.

Based on JDK-8215297.

CR:
https://bugs.openjdk.java.net/browse/JDK-8238220
Webrev:
http://cr.openjdk.java.net/~tschatzl/8238220/webrev/
Testing:
local compilation

Thanks,
   Thomas