SOLR-6670: change BALANCESLICEUNIQUE to BALANCESHARDUNIQUE. corrected typo

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/branches/branch_5x@1636364 13f79535-47bb-0310-9956-ffa450edef68
LUCENE-6044: Fixed backcompat support for token filters with enablePositionIncrements=false

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/branches/branch_5x@1636368 13f79535-47bb-0310-9956-ffa450edef68