Add "%.po-update" and "update-po" targets to Makefile.

Those can be used as a shortcut to msgmerge(1) to update one
("$locale.po-update") or all ("update-po") portable object files with
new strings from the message catalog ("aur.pot").

Signed-off-by: Lukas Fleischer <archlinux@cryptocrack.de>

po/Makefile

@@ -26,6 +26,8 @@ POFILES = \
 MOFILES = ${POFILES:.po=.mo}
 LOCALES = ${MOFILES:.mo=}
 
+UPDATEPOFILES = ${POFILES:.po=.po-update}
+
 MSGID_BUGS_ADDRESS = https://bugs.archlinux.org/index.php?project=2
 
 all: ${MOFILES}
@@ -33,6 +35,10 @@ all: ${MOFILES}
 %.mo: %.po
 	msgfmt -o $@ $<
 
+%.po-update: %.po aur.pot
+	lang=`echo $@ | sed -e 's/\.po-update$$//'`; \
+	msgmerge -U --no-location --lang="$$lang" $< aur.pot
+
 update-pot:
 	pkgname=AUR; \
 	pkgver=`sed -n 's/.*"AUR_VERSION", "\(.*\)".*/\1/p' ../web/lib/version.inc`; \
@@ -42,8 +48,11 @@ update-pot:
 		--msgid-bugs-address='${MSGID_BUGS_ADDRESS}' \
 		--directory ../web --files-from POTFILES -o aur.pot
 
+update-po:
+	${MAKE} ${UPDATEPOFILES}
+
 clean:
-	rm *.mo
+	rm *.mo *.po\~
 
 install: all
 	for l in ${LOCALES}; do mkdir -p ${DESTDIR}${PREFIX}/$$l/LC_MESSAGES/; done
@@ -52,4 +61,4 @@ install: all
 uninstall:
 	for l in ${LOCALES}; do rm -rf ${DESTDIR}${PREFIX}/$$l/LC_MESSAGES/; done
 
-.PHONY: all update-pot clean install uninstall
+.PHONY: all update-pot update-po clean install uninstall