Finished docs make rules.

docs/rules.mk

@@ -7,7 +7,7 @@ PDFLATEX_FLAGS = -halt-on-error -interaction=nonstopmode \
 docs: $(b)proposal.pdf $(b)presentation.pdf $(b)$(REPORT).pdf $(b)$(REPORT).bbl
 
 $(b)%.pdf: $(d)%.tex
-	mkdir -p `dirname $@`
+	mkdir -p $(@D)
 	TEXINPUTS=$(d): pdflatex ${PDFLATEX_FLAGS} $^
 
 $(b)$(REPORT).bbl: $(d)$(REPORT).bib