SOLR-6843: JMX RMI connector should be disabled by default but can be activated by setting ENABLE_REMOTE_JMX_OPTS to true in solr.in.(sh|cmd).

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1644978 13f79535-47bb-0310-9956-ffa450edef68
SOLR-6844: Rename ConfigSolr.getZkHostPort(), which actually returns the Solr port, to .getSolrHostPort()

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1645034 13f79535-47bb-0310-9956-ffa450edef68