Simplify the svn_wc__merge_props() API by restricting it to doing a merge.
Rather than this function also updating the pristine properties with the
same changes, let the callers that need that do that separately.

* subversion/include/private/svn_subr_private.h,
  subversion/libsvn_subr/properties.c
  (svn_prop__patch): New function.

* subversion/libsvn_wc/props.h,
  subversion/libsvn_wc/props.c
  (svn_wc__merge_props): Remove the 'new_pristine_props' output parameter.
  (svn_wc_merge_props3): Adjust caller.

* subversion/libsvn_wc/merge.c
  (svn_wc_merge5): Adjust caller.

* subversion/libsvn_wc/externals.c
  (close_file): Update the pristine properties separately, using
    svn_prop__patch(), before calling svn_wc__merge_props().

* subversion/libsvn_wc/update_editor.c
  (close_directory, close_file): Same.

* subversion/libsvn_wc/wc_db_update_move.c
  (update_working_props): Same.


git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1428452 13f79535-47bb-0310-9956-ffa450edef68