LUCENE-5759: Add PackedInts.unsignedBitsRequired.


git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1602873 13f79535-47bb-0310-9956-ffa450edef68
LUCENE-5764: Add tests to DocIdSet.ramBytesUsed.


git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1602876 13f79535-47bb-0310-9956-ffa450edef68
LUCENE-5765: Add tests to OrdinalMap.ramBytesUsed.


git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1602880 13f79535-47bb-0310-9956-ffa450edef68