some minor fixe

Makefile

@@ -36,9 +36,11 @@ watchpdf :
 watchscript :
 	while true; do ! make -s -q script && make script; sleep 0.5; done
 
-
-clean :
+cleantex:
 	rm -f *~  $(BASENAME).aux $(BASENAME).log $(BASENAME).out $(BASENAME)-solutions.tex $(BASENAME).toc $(BASENAME).lo?  $(BASENAME).idx $(BASENAME)-term.i* $(BASENAME)-enterm.i* $(BASENAME)-code.i*
+	for sd in $(SUBDIRS); do $(MAKE) -C $$sd/lecture cleantex; done
+
+clean : cleantex
 	for sd in $(SUBDIRS); do $(MAKE) -C $$sd/lecture clean; done
 
 cleanall : clean