Merged revision(s) 1596057 from lucene/dev/trunk:
LUCENE-5678: Use FileOutputStream instead of RandomAccessFile to write index data. BufferedIndexOutput and related APIs were removed.

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/branches/branch_4x@1599548 13f79535-47bb-0310-9956-ffa450edef68