LUCENE-5724: fix CompoundFileWriter to not suppress the incoming IOContext

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1599291 13f79535-47bb-0310-9956-ffa450edef68
LUCENE-5724: add CHANGES

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1599292 13f79535-47bb-0310-9956-ffa450edef68