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>

diff-lib.c

@@ -664,7 +664,7 @@ int run_diff_index(struct rev_info *revs, int cached)
 	const char *tree_name;
 	int match_missing = 0;
 
-	/* 
+	/*
 	 * Backward compatibility wart - "diff-index -m" does
 	 * not mean "do not ignore merges", but totally different.
 	 */