Make the editor path driver callback a little easier to use.
Add 'editor' and 'edit_baton' parameters to the path driver callback. All but trivial callback implementations need these, and they otherwise had to be passed through the callback baton, which was straightforward but more trouble than it need be.
* subversion/libsvn_delta/path_driver.c (svn_delta_path_driver3): Rename from 'svn_delta_path_driver2'. (svn_delta_path_driver_state_t, svn_delta_path_driver_start): Change the callback function type. (svn_delta_path_driver_step): Pass the extra parameters.
* subversion/libsvn_client/shelf.c (path_driver_cb_func): Take 'editor' and 'edit_baton' as direct parameters. (path_driver_cb_baton_t, svn_client__shelf_replay): Remove them from the path driver baton.