Switch to fltk graphics if possible

src/foo.m

@@ -3,6 +3,8 @@
 clear all
 close all
 
+if exist('graphics_toolkit','file') graphics_toolkit('fltk') end
+
 x = -200:2:300;
 y = -200:2:300;
 [X, Y] = meshgrid(x,y);