Remove illustration*.* in clean target.

Rev: tutorial/Makefile:1.53

tutorial/Makefile

@@ -103,6 +103,7 @@ the_image_module.html: Image.wmml the_image_module.wmml
 
 clean:
 	-rm -f *.html *.md $(MADEFILES)
+	-rm -f illustration*.*
 	-rm -f tutorial.dvi tutorial.tex tutorial.aux
 	-rm -f tutorial.log tutorial.toc
 	-rm -f latex.wcache pdflatex.wcache illustration_cache image_cache gfx/* execute_cache