SOLR-5416: CollapsingQParserPlugin bug with tagging

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1551999 13f79535-47bb-0310-9956-ffa450edef68
SOLR-5556: Allow CollectionsHandler and InfoHandler classes to be specified in solr.xml

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1552044 13f79535-47bb-0310-9956-ffa450edef68