SOLR-5285: Added a new [child ...] DocTransformer for optionally including Block-Join decendent documents inline in the results of a search (merge r1601028)

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/branches/branch_4x@1601037 13f79535-47bb-0310-9956-ffa450edef68
SOLR-5285: use FieldType methods to be less brittle (merge r1601044)

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/branches/branch_4x@1601052 13f79535-47bb-0310-9956-ffa450edef68