SOLR-5552: Leader recovery process can select the wrong leader if all replicas for a shard are down and trying to recover as well as lose updates that should have been recovered.
SOLR-5569 A replica should not try and recover from a leader until it has published that it is ACTIVE. 
SOLR-5568 A SolrCore cannot decide to be the leader just because the cluster state says no other SolrCore's are active. 

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/branches/branch_4x@1553034 13f79535-47bb-0310-9956-ffa450edef68