SOLR-6233: Minor refactorings provided by Steve Davids.

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1626802 13f79535-47bb-0310-9956-ffa450edef68
SOLR-6481: CLUSTERSTATUS action should consult /live_nodes when reporting the state of a replica

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1626818 13f79535-47bb-0310-9956-ffa450edef68
SOLR-6484: SolrCLI's healthcheck action needs to check live nodes as part of reporting the status of a replica

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1626823 13f79535-47bb-0310-9956-ffa450edef68
LUCENE-5969: let AssertingCodec implement RandomAccessOrds, and test it directly too

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1626826 13f79535-47bb-0310-9956-ffa450edef68
SOLR-6486: solr start script can have a debug flag option; use -a to set arbitrary options.

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1626833 13f79535-47bb-0310-9956-ffa450edef68