Adjust svnadmin_tests to expect packing/sharding.
Adjust svnadmin_tests to expect packing/sharding.

* subversion/tests/cmdline/svnadmin_tests.py
  (fsfs_file):
    Give the path to the pack file, if necessary (analogously to
    svn_fs_fs__path_rev_absolute).
  (verify_incremental_fsfs):
    Skip editing r2 if it is in a pack file.
  (fsfs_recover_handle_missing_revs_or_revprops_file):
    Adjust paths and expected error messages.

jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion