SOLR-6365 <paramSet> renamed to <initParams>

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/branches/branch_5x@1626052 13f79535-47bb-0310-9956-ffa450edef68
LUCENE-5944: backport changes to branch_5x, except in-flux changes (o.a.l.document change, removal of solr .war), plus merge changes entries, plus fix solr precommit, plus fix docs, plus keep standardtokenizer 4.0 grammar for back compat

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/branches/branch_5x@1626055 13f79535-47bb-0310-9956-ffa450edef68