Merge pull request #38 from bmwiedemann/master

allow to use source date for man page generation

man/Makefile.am

@@ -1,5 +1,5 @@
 .0.1:
-	@sed -e "s/!VERSION!/@JACK_RELEASE@/g" -e "s/!DATE!/`date '+%B %Y'`/g" < $*.0 > $@
+	@[ -z "$$SOURCE_DATE_EPOCH" ] || d=--date=@$$SOURCE_DATE_EPOCH ; sed -e "s/!VERSION!/@JACK_RELEASE@/g" -e "s/!DATE!/`date $$d '+%B %Y'`/g" < $*.0 > $@
 	@echo Built $*.1 from template
 
 manpages = $(patsubst %.0,%.1,$(wildcard *.0))