Prevent svn diff --old X --new Y from recursing into .svn directories.
Prevent svn diff --old X --new Y from recursing into .svn directories.

* subversion/libsvn_client/diff.c
  (arbitrary_diff_walker_baton): New members RECURSING_WITHIN_ADM_DIR,
   AMD_DIR_ABSPATH, and POOL.
  (do_arbitrary_dirs_diff): Initialise new baton members.
  (arbitrary_diff_walker): Skip anything at or within administrative
   directories.


git-svn-id: f8a4e5e023278da1e04e203c7fe051e3c4285d88@1311697 13f79535-47bb-0310-9956-ffa450edef68

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