Changed from nThreads to receiving an ExecutorService

There are a lot of different models/versions of executorservices, also
varying according to client JDK level. Give client full control of how the
executor service is created and also possibly how to schedule tasks through
a slightly lower-level cerateCallable/submit api.

Termination of ExecutorService is still controlled by ParallelScatterZipCreator,
as must be.

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/compress/trunk@1651285 13f79535-47bb-0310-9956-ffa450edef68
2 files changed