SOLR-5691: Sharing non thread safe WeakHashMap across thread can cause problems. 

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/branches/branch_4x@1565070 13f79535-47bb-0310-9956-ffa450edef68
SOLR-5672: Add logParamsList parameter to support reduced logging. Closes #23.

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/branches/branch_4x@1565075 13f79535-47bb-0310-9956-ffa450edef68