Add <keypad begin> to antialias the image (other keypad keys don't do this)

TODO

@@ -15,3 +15,6 @@ then resizing the window) causing imlib2 warnings.
 
 --fmmode is neither documented nor implemented. Either implement or
 remove it.
+
+<keypad begin> antialieses the image, but doing that automatically upon
+key release would be better.

feh.1

@@ -562,6 +562,15 @@ Quit feh
 Move the image to the left
 .B <KEYPAD RIGHT>
 Move the image to the right
+.B <KEYPAD UP>
+Move the image up
+.B <KEYPAD DOWN>
+Move the image down
+.B <KEYPAD BEGIN>
+Antialias the image.
+When controlling feh with the mouse, this is done by default as soon as the
+respective mouse button is released; in keypad mode, you need to press this
+button.
 .B <KEYPAD +>
 Zoom in
 .B <KEYPAD ->

src/keyevents.c

@@ -304,15 +304,18 @@ feh_event_handle_keypress(XEvent * ev)
      case XK_KP_Subtract:
         winwid->zoom = winwid->zoom * 0.75;
         winwidget_render_image(winwid, 0, 0);
-	break;
+        break;
      case XK_KP_Multiply:
         winwid->zoom = 1;
         winwidget_render_image(winwid, 0, 0);
-	break;
+        break;
      case XK_KP_Divide:
         feh_calc_needed_zoom(&winwid->zoom, winwid->im_w, winwid->im_h, winwid->w, winwid->h);
         winwidget_render_image(winwid, 0, 0);
-	break;
+        break;
+     case XK_KP_Begin:
+        winwidget_render_image(winwid, 0, 1);
+        break;
      default:
         break;
    }

src/options.c

@@ -1123,6 +1123,9 @@ show_usage(void)
 " q, Q                       Quit the slideshow\n"
 " <KEYPAD LEFT>              Move the image to the left\n"
 " <KEYPAD RIGHT>             Move the image to the right\n"
+" <KEYPAD UP>                Move the image up\n"
+" <KEYPAD DOWN>              Move the image down\n"
+" <KEYPAD BEGIN>             Antialias the image\n"
 " <KEYPAD +>                 Zoom in\n"
 " <KEYPAD ->                 Zoom out\n"
 " <KEYPAD *>                 Zoom to 100%%\n"