gitk: Replace "next" and "prev" buttons with down and up arrows

Users often find that "next" and "prev" do the opposite of what they
expect.  For example, "next" moves to the next match down the list, but
that is almost always backwards in time.  Replacing the text with arrows
makes it clear where the buttons will take the user.

Signed-off-by: Marc Branchaud <marcnarc@xiplink.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>

gitk

@@ -2263,9 +2263,35 @@ proc makewindow {} {
 
     # build up the bottom bar of upper window
     ${NS}::label .tf.lbar.flabel -text "[mc "Find"] "
-    ${NS}::button .tf.lbar.fnext -text [mc "next"] -command {dofind 1 1}
-    ${NS}::button .tf.lbar.fprev -text [mc "prev"] -command {dofind -1 1}
+
+    set bm_down_data {
+	#define down_width 16
+	#define down_height 16
+	static unsigned char down_bits[] = {
+	0x80, 0x01, 0x80, 0x01, 0x80, 0x01, 0x80, 0x01,
+	0x80, 0x01, 0x80, 0x01, 0x80, 0x01, 0x80, 0x01,
+	0x87, 0xe1, 0x8e, 0x71, 0x9c, 0x39, 0xb8, 0x1d,
+	0xf0, 0x0f, 0xe0, 0x07, 0xc0, 0x03, 0x80, 0x01};
+    }
+    image create bitmap bm-down -data $bm_down_data -foreground $uifgcolor
+    ${NS}::button .tf.lbar.fnext -width 26 -command {dofind 1 1}
+    .tf.lbar.fnext configure -image bm-down
+
+    set bm_up_data {
+	#define up_width 16
+	#define up_height 16
+	static unsigned char up_bits[] = {
+	0x80, 0x01, 0xc0, 0x03, 0xe0, 0x07, 0xf0, 0x0f,
+	0xb8, 0x1d, 0x9c, 0x39, 0x8e, 0x71, 0x87, 0xe1,
+	0x80, 0x01, 0x80, 0x01, 0x80, 0x01, 0x80, 0x01,
+	0x80, 0x01, 0x80, 0x01, 0x80, 0x01, 0x80, 0x01};
+    }
+    image create bitmap bm-up -data $bm_up_data -foreground $uifgcolor
+    ${NS}::button .tf.lbar.fprev -width 26 -command {dofind -1 1}
+    .tf.lbar.fprev configure -image bm-up
+
     ${NS}::label .tf.lbar.flab2 -text " [mc "commit"] "
+
     pack .tf.lbar.flabel .tf.lbar.fnext .tf.lbar.fprev .tf.lbar.flab2 \
 	-side left -fill y
     set gdttype [mc "containing:"]