SOLR-5190: SolrEntityProcessor substitutes variables only once in child entities

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1518161 13f79535-47bb-0310-9956-ffa450edef68
LUCENE-4818 - removed DV based method as it's not compatible with TVs
Merge branch 'trunk' of http://git.apache.org/lucene-solr into lucene-4818