On the fsfs-format7 branch:  Complete the FSX hotcopy code to
handle the index files as well.

* subversion/libsvn_fs_x/hotcopy.c
  (hotcopy_copy_shard_file): copy index files if specified
  (hotcopy_copy_packed_shard,
   hotcopy_body): update caller
  (hotcopy_remove_file): new utility
  (hotcopy_remove_rev_files): use the new util to clean up stale index files too


git-svn-id: https://svn.apache.org/repos/asf/subversion/branches/fsfs-format7@1507720 13f79535-47bb-0310-9956-ffa450edef68