LUCENE-5113: Added (Monotonic)AppendingLongBuffer.freeze to pack the pending values.


git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1503578 13f79535-47bb-0310-9956-ffa450edef68
LUCENE-5115: WAHDocIdSet's iterator cost() function now returns the exact cardinality of the set.


git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1503617 13f79535-47bb-0310-9956-ffa450edef68