doc: add pdf targets

Hello Stephen-

Here is one more patch that SUSE has been carrying.

Cheers, Brandon

doc/Makefile

@@ -15,6 +15,7 @@ PAGESPERPAGE=2
 
 HTMLFILES=$(subst .sgml,.html,$(shell echo *.sgml))
 DVIFILES=$(subst .ps,.dvi,$(PSFILES))
+PDFFILES=$(subst .ps,.pdf,$(PSFILES))
 
 
 all: pstwocol
@@ -25,6 +26,8 @@ html: $(HTMLFILES)
 
 dvi: $(DVIFILES)
 
+pdf: $(PDFFILES)
+
 print: $(PSFILES)
 	$(LPR) $(PSFILES)
 
@@ -41,6 +44,11 @@ print: $(PSFILES)
 		echo "Re-running LaTeX $<, $${pass}d pass"; pass=$$[$$pass + 1]; \
 	done
 
+#%.pdf: %.tex
+#	pdflatex $<
+%.pdf: %.ps
+	ps2pdf $<
+
 %.ps: %.dvi
 	$(DVIPS) $< -o $@