Fixed make rules for presentation.

docs/rules.mk

@@ -1,7 +1,9 @@
 .PHONY: docs
 
-docs: $(b)proposal.pdf $(b)report.pdf
+docs: $(b)proposal.pdf $(b)presentation.pdf $(b)report.pdf
 
 $(b)%.pdf: $(d)%.tex
 	mkdir -p `dirname $@`
-	pdflatex -halt-on-error -interaction=nonstopmode -output-directory `dirname $@` $^
+	cd $(d); \
+	pdflatex -halt-on-error -interaction=nonstopmode \
+		-output-directory "../`dirname $@`" `basename $^`