HBASE-8848 Backport hbase-6979 "recovered.edits file should not break distributed log splitting"

git-svn-id: https://svn.apache.org/repos/asf/hbase/branches/0.94@1499499 13f79535-47bb-0310-9956-ffa450edef68
HBASE-8814 Possible NPE in split if a region has empty store files; REVERT.  FAILING TEST

git-svn-id: https://svn.apache.org/repos/asf/hbase/branches/0.94@1499564 13f79535-47bb-0310-9956-ffa450edef68