SOLR-3939: Consider a sync attempt from leader to replica that fails due to 404 a success.
SOLR-3940: Rejoining the leader election incorrectly triggers the code path for a fresh cluster start rather than fail over.

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1397665 13f79535-47bb-0310-9956-ffa450edef68
8 files changed