LUCENE-5055: "rat-sources" target now checks also build.xml, ivy.xml, forbidden-api signatures, and parts of resources folders.

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1493333 13f79535-47bb-0310-9956-ffa450edef68
remove stale comment

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1493345 13f79535-47bb-0310-9956-ffa450edef68
fix NPE on empty index

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1493381 13f79535-47bb-0310-9956-ffa450edef68
fix test failure

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1493391 13f79535-47bb-0310-9956-ffa450edef68