configure: add check for the program "msgfmt" when i18n is requested

The program may not be installed because it is not needed for non-dev
activities, so it is better to check at the beginning than to let the
compilation fail later. The check is done only if the user has specified
that he wants to install translations.

Took the opportunity to make the generation of "mo" file follow the silent
rules in Makefiles if user enabled them.

Signed-off-by: Christophe <curis@Ares.blacknet.hell>

WINGs/po/Makefile.am

@@ -74,7 +74,7 @@ POTFILES += \
 SUFFIXES = .po .mo
 
 .po.mo: 
-	msgfmt -c -o $@ $<
+	$(AM_V_GEN)$(MSGFMT) -c -o $@ $<
 
 
 all-local: $(CATALOGS)

WPrefs.app/po/Makefile.am

@@ -40,7 +40,7 @@ POTFILES  = \
 SUFFIXES = .po .mo
 
 .po.mo: 
-	msgfmt -c -o $@ $<
+	$(AM_V_GEN)$(MSGFMT) -c -o $@ $<
 
 
 all-local: $(CATALOGS)

m4/wm_i18n.m4

@@ -47,6 +47,11 @@ AS_IF([test "x$LINGUAS" != "x"],
         [AC_MSG_ERROR([support for internationalization requested, but gettext was not found])])
      LIBS="$wm_save_LIBS"
      dnl
+     dnl The program 'msgfmt' is needed to convert the 'po' files into 'mo' files
+     AC_CHECK_PROG([MSGFMT], [msgfmt], [msgfmt])
+     AS_IF([test "x$MSGFMT" = "x"],
+         [AC_MSG_ERROR([the program 'msgfmt' is mandatory to install translation - do you miss the package 'gettext'?])])
+     dnl
      dnl Environment is sane, let's continue
      AC_DEFINE([I18N], [1], [Internationalization (I18N) support (set by configure)])
      supported_locales=""

po/Makefile.am

@@ -69,7 +69,7 @@ POTFILES  = \
 SUFFIXES = .po .mo
 
 .po.mo: 
-	msgfmt -c -o $@ $<
+	$(AM_V_GEN)$(MSGFMT) -c -o $@ $<
 
 
 all-local: $(CATALOGS)

util/po/Makefile.am

@@ -15,7 +15,7 @@ POTFILES  = \
 SUFFIXES = .po .mo
 
 .po.mo:
-	msgfmt -c -o $@ $<
+	$(AM_V_GEN)$(MSGFMT) -c -o $@ $<
 
 
 all-local: $(CATALOGS)