On the fsfs-format7 branch: Adapt transction code to latest API changes and
make transactions create the log<->phys indexes.

* subversion/libsvn_fs_fs/transaction.c
  (store_l2p_index_entry,
   store_p2l_index_entry): new utility functions write index records
  (allocate_item_index): new utility function to allocate an item index
  (rep_write_get_baton): s/base_offset/base_item_index
  (rep_write_contents_close,
   write_hash_rep,
   write_hash_delta_rep): store item indexes instead of offsets;
   update proto indexes
  (write_final_rev): drop item_index parameter as it gets allocated
   dynamically; adapt to API / signature changes; disable issue #3845
   code for format7 repos for the time being; explicitly store root
   noderev item in l2p index; add noderevs to p2l index
  (write_final_changed_path_info): add entry for changes list to indexes
  (commit_body): adapt to API / signature changes; create final indexes


git-svn-id: https://svn.apache.org/repos/asf/subversion/branches/fsfs-format7@1434449 13f79535-47bb-0310-9956-ffa450edef68