diff: honor flag -i (ignore case differences)

diff: honor flag -i (ignore case differences)

>>From 503a1e1d2597f7cdf86a9ea39ebd2aee050ca759 Mon Sep 17 00:00:00 2001
From: Matheus Izvekov <mizvekov@gmail.com>
Date: Mon, 18 Jan 2010 14:06:26 -0200
Subject: [PATCH] diff: honor flag -i (ignore case differences)

function                                             old     new   delta
read_token                                           157     178     +21
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 1/0 up/down: 21/0)               Total: 21 bytes
   text	   data	    bss	    dec	    hex	filename
  70102	    733	   8576	  79411	  13633	busybox_old
  70123	    733	   8576	  79432	  13648	busybox_unstripped

Signed-off-by: Matheus Izvekov <mizvekov@gmail.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>