LUCENE-5377: IW.addIndexes(Dir[]) causes silent index corruption

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1560401 13f79535-47bb-0310-9956-ffa450edef68
LUCENE-5377: remove dead code

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1560405 13f79535-47bb-0310-9956-ffa450edef68
SOLR-5594: Allow FieldTypes to specify custom PrefixQuery behavior

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1560412 13f79535-47bb-0310-9956-ffa450edef68
SOLR-5657: When a SolrCore starts on HDFS, it should gracefully handle HDFS being in safe mode.

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1560553 13f79535-47bb-0310-9956-ffa450edef68
tests: try harder to not kill the last replica in a shard

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1560557 13f79535-47bb-0310-9956-ffa450edef68