SOLR-6069: The 'clusterstatus' API should return 'roles' information

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1606034 13f79535-47bb-0310-9956-ffa450edef68
SOLR-6044: The 'clusterstatus' API should return live_nodes as well

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1606046 13f79535-47bb-0310-9956-ffa450edef68