Make the revprop access robust against corrupted pack files that
claim to cover / contain revision ranges either not packed or outside
the current shard.  This is to prevent manifest index overflows
further down the road.

* subversion/libsvn_fs_fs/fs_fs.c
  (same_shard): new utility
  (parse_packed_revprops): verify revprop pack file revision range

git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1515516 13f79535-47bb-0310-9956-ffa450edef68