Ev2 shims: Handle the absent operations when converting from Ev2 to the delta editor.
Ev2 shims: Handle the absent operations when converting from Ev2 to the delta
editor.

* subversion/libsvn_delta/compat.c
  (operation): New operation.
  (build): Handle the add absent action.
  (add_absent_cb): Create an absent node in the operation tree.
  (drive): Process the absent operation appropriately.


git-svn-id: f8a4e5e023278da1e04e203c7fe051e3c4285d88@1204735 13f79535-47bb-0310-9956-ffa450edef68

YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion