On the 'move-tracking-2' branch: Implement update-editor shims, but don't
yet try to use them.

* subversion/include/private/svn_editor3.h
  (svn_editor3__set_target_revision_func_t,
   svn_update_editor3_t,
   svn_delta__ev3_from_delta_for_update,
   svn_delta__delta_from_ev3_for_update): New.

* subversion/include/private/svn_ra_private.h
  (svn_ra_do_update4,
   svn_ra_do_switch4): New.

* subversion/include/private/svn_wc_private.h
  (svn_wc__get_update_editor_ev3,
   svn_wc__get_switch_editor_ev3): New.

* subversion/libsvn_client/switch.c
  (switch_internal): Implement use of Ev3 switch editor, but ifdef'd out as
    some tests fail.

* subversion/libsvn_client/update.c
  (update_internal): Implement use of Ev3 update editor, but ifdef'd out as
    some tests fail.

* subversion/libsvn_delta/compat3.c
  (svn_delta__delta_from_ev3_for_update,
   svn_delta__ev3_from_delta_for_update): New.

* subversion/libsvn_ra_local/ra_plugin.c
  (fetch_baton_t,
   fetch_func,
   svn_ra_local__do_update_ev3,
   svn_ra_local__do_switch_ev3): New.
  (ra_local_vtable): Add the two new methods.

* subversion/libsvn_ra/ra_loader.c
  (svn_ra_do_update4, svn_ra_do_switch4): New, simple wrappers calling the
    new vtable methods.

* subversion/libsvn_ra/ra_loader.h
  (svn_ra__vtable_t): Add the two new methods.

* subversion/libsvn_ra_serf/serf.c
  (serf_vtable): Add place-holder null entries for the two new methods; no
    fall-back is implemented for this RA layer yet.

* subversion/libsvn_ra_svn/client.c
  (ra_svn_vtable): Same.

* subversion/libsvn_wc/deprecated.c
  (svn_wc_get_update_editor4): Wrap the new Ev3 implementation, inserting an
    Ev1/Ev3 shim.

* subversion/libsvn_wc/update_editor.c
  (make_editor3,
   svn_wc__get_update_editor_ev3,
   svn_wc__get_switch_editor_ev3): New.
  (svn_wc__get_switch_editor): Add backward compatibility code, wrapping the
    new make_editor3(), but ifdef'd out.

* subversion/libsvn_wc/util.c
  (svn_wc__fetch_func): New.

* subversion/libsvn_wc/wc.h
  (svn_wc__shim_fetch_baton_t): Add a member and a comment.
  (svn_wc__fetch_func): Declare.


git-svn-id: https://svn.apache.org/repos/asf/subversion/branches/move-tracking-2@1624054 13f79535-47bb-0310-9956-ffa450edef68