$(pandoc) -s -t man < $< > $@+ && mv $@+ $@
txt2pre = ./Documentation/txt2pre < $< > $@+ && touch -r $< $@+ && mv $@+ $@
-txt := INSTALL README COPYING
+txt := INSTALL README COPYING TODO
dtxt := design_notes.txt design_www.txt dc-dlvr-spam-flow.txt
dtxt := $(addprefix Documentation/, $(dtxt))