SOLR-5541: Use StrUtils.splitSmart to handle escape chars

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1565520 13f79535-47bb-0310-9956-ffa450edef68
SOLR-5644: SplitShard does not handle not finding a shard leader well

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1565555 13f79535-47bb-0310-9956-ffa450edef68
SOLR-5659: Add test for compositeId ending with a separator char

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1565572 13f79535-47bb-0310-9956-ffa450edef68
LUCENE-5434: fix test bug: this test case uses a non-NRT reader too

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1565617 13f79535-47bb-0310-9956-ffa450edef68