Make statusbar optional (#95)

libXft and libfontconfig are now optional dependencies which can be
disabled via `HAVE_LIBFONTS=0`. Disabling them means disabling the
statusbar. This also does not search for freetype2 header if disabled.

Co-authored-by: NRK <nrk@disroot.org>

image.c

@@ -643,7 +643,7 @@ void img_render(img_t *img)
 			}
 			imlib_image_put_back_data(data);
 		} else {
-			c = win->win_bg.pixel;
+			c = win->win_bg;
 			imlib_context_set_color(c >> 16 & 0xFF, c >> 8 & 0xFF, c & 0xFF, 0xFF);
 			imlib_image_fill_rectangle(0, 0, dw, dh);
 		}