War on whitespace

This uses "git-apply --whitespace=strip" to fix whitespace errors that have
crept in to our source files over time.  There are a few files that need
to have trailing whitespaces (most notably, test vectors).  The results
still passes the test, and build result in Documentation/ area is unchanged.

Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/howto/rebuild-from-update-hook.txt

@@ -84,4 +84,3 @@ There are four things worth mentioning:
  - This is still crude and does not protect against simultaneous
    make invocations stomping on each other.  I would need to add
    some locking mechanism for this.
-