On the fsfs-format7 branch: Use logical addressing in representations
as well and adapt the data read access function to the recent API
changes.

* subversion/libsvn_fs_fs/low_level.h
  (svn_fs_fs__rep_header_t): replace base_offset by base_item_index

* subversion/libsvn_fs_fs/low_level.c
  (svn_fs_fs__parse_representation,
   svn_fs_fs__unparse_representation): s/offset/item_index
  (svn_fs_fs__read_rep_header,
   svn_fs_fs__write_rep_header): s/base_offset/base_item_index

* subversion/libsvn_fs_fs/cached_data.c
  (open_and_seek_revision): adapt to API changes
  (open_and_seek_transaction,
   create_rep_state_body): translate item index to offset
  (open_and_seek_representation,
   svn_fs_fs__get_contents,
   svn_fs_fs__try_process_file_contents,
   svn_fs_fs__get_proplist): s/offset/item_index
  (svn_fs_fs__rev_get_root
   svn_fs_fs__get_changes): use fixed item index for format7
  (build_rep_list,
   svn_fs_fs__get_file_delta_stream): s/base_offset/base_item_index


git-svn-id: https://svn.apache.org/repos/asf/subversion/branches/fsfs-format7@1434431 13f79535-47bb-0310-9956-ffa450edef68