Merged revision(s) 1637665 from lucene/dev/trunk:
LUCENE-5953: Restructure Directory and LockFactory APIs

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/branches/branch_5x@1637674 13f79535-47bb-0310-9956-ffa450edef68
Merged revision(s) 1637688 from lucene/dev/trunk:
LUCENE-5953: Remove obsolete locking

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/branches/branch_5x@1637689 13f79535-47bb-0310-9956-ffa450edef68