SOLR-5824: Merge up Solr MapReduce contrib code to latest external changes. Includes a few minor bug fixes.

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/branches/branch_4x@1579322 13f79535-47bb-0310-9956-ffa450edef68
tests: Add SuppressSSL to ChaosMOnkeyNothingIsSafeTest.

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/branches/branch_4x@1579325 13f79535-47bb-0310-9956-ffa450edef68