Custom bar colors (#10)

* set bar and text colors independently

* change xresources to Program.class.resource

* rename color variables to win/bar_bg/fg

* change default bar colors to match window colors

image.c

@@ -500,7 +500,7 @@ void img_render(img_t *img)
 			}
 			imlib_image_put_back_data(data);
 		} else {
-			c = win->bg.pixel;
+			c = win->win_bg.pixel;
 			imlib_context_set_color(c >> 16 & 0xFF, c >> 8 & 0xFF, c & 0xFF, 0xFF);
 			imlib_image_fill_rectangle(0, 0, dw, dh);
 		}