LUCENE-5933: fix eol-style

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/branches/branch_4x@1624359 13f79535-47bb-0310-9956-ffa450edef68
LUCENE-5925: use rename instead of segments_N fallback/segments.gen

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/branches/branch_4x@1624362 13f79535-47bb-0310-9956-ffa450edef68