LUCENE-5207: replace tabs by 2 spaces now. antlr 3.5 produces tabs consistently now, so we can replace them (no mixed tabs anymore)

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/branches/lucene5207@1523046 13f79535-47bb-0310-9956-ffa450edef68
LUCENE-5207: upgrade checksum/maven

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/branches/lucene5207@1523047 13f79535-47bb-0310-9956-ffa450edef68