LUCENE-4810: position increment for first output token from EdgeNGramTokenFilter must be > 0

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/branches/lucene_solr_4_3@1470502 13f79535-47bb-0310-9956-ffa450edef68
SOLR-4746: fix JSON output for distributed grouping top level

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/branches/lucene_solr_4_3@1470534 13f79535-47bb-0310-9956-ffa450edef68