[PATCH 0/3] diff overhaul

[Junio C Hamano <junkio@cox.net>]

Here are three patches to update diff we discussed earlier.

  [PATCH 1/3] Update mode-change strings in diff output.
  [PATCH 2/3] Rename git-diff-tree-helper to git-diff-helper.
  [PATCH 3/3] Rename git-diff-tree-helper to git-diff-helper (part 2).

The first one is to normalize the mode bits output to be more
machine friendly, which we discussed.

The second commit records only renames for two files and there
is no content change.  The third one is to change the Makefiles,
documentation, and also usage string in git-diff-helper itself.

I am deliverately doing the 2 and 3 in separate steps for two
reasons.  (1) to reduce the possibility of mistakes during the
rename for myself; (2) people doing the git repository browser
can use the commit trail for practicing their rename detection
logic.  So please keep these two steps separate when you commit.