SOLR-5609 Don't let cores create slices/named replicas , SOLR-5130 addReplica Collections API

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1571276 13f79535-47bb-0310-9956-ffa450edef68
Merge remote-tracking branch 'upstream/trunk' into trunk