Remove ImageDisplay, it is useless, again

lib/tailor/GUI/ImageDisplay.rb

@@ -1,22 +0,0 @@
-module Tailor
-  module GUI
-    class ImageDisplay < Wx::Panel
-      def initialize(*args)
-        super(*args)
-        @bitmap = nil
-      end
-
-      def set_image image
-        @bitmap = image.to_bitmap
-        refresh
-      end
-      
-      def on_draw dc
-        dc.set_background Wx::WHITE_BRUSH
-        dc.clear
-        return if @bitmap == nil
-        dc.draw_bitmap(@bitmap, 0, 0, true)
-      end
-    end
-  end
-end