nm: Install the .name file into /usr/lib/NetworkManager/VPN

It's the preferred location for system-provided plugins.

A compatible file in /etc is still kept. Also, the compatibility /etc
file needs to use a full path due to a bug in GNOME Shell.

The full path to a arch-dependent file in a supposedly arch-independent
file is a sin and a multilib violation in some distributions. However.
some pre-release versions of NetworkManager-1.2 as shipped by
distributions require a full path. Let's keep a configure-time option
for that.

src/frontends/gnome/Makefile.am

@@ -2,7 +2,7 @@ AUTOMAKE_OPTIONS = foreign
 
 SUBDIRS = properties auth-dialog po
 
-nmvpnservicedir = $(sysconfdir)/NetworkManager/VPN
+nmvpnservicedir = $(prefix)/lib/NetworkManager/VPN
 nmvpnservice_DATA = nm-strongswan-service.name
 
 @INTLTOOL_DESKTOP_RULE@
@@ -12,9 +12,24 @@ appdata_DATA = $(appdata_in_files:.xml.in=.xml)
 appdata_in_files = NetworkManager-strongswan.appdata.xml.in
 @INTLTOOL_XML_RULE@
 
+# Install a file with full path to plugins for an old gnome-shell
+# https://bugzilla.gnome.org/show_bug.cgi?id=693590
+install-data-hook:
+	mkdir -p $(DESTDIR)$(sysconfdir)/NetworkManager/VPN
+	sed -e "1s|^|# This file is obsoleted by a file in $(NM_VPN_SERVICE_DIR)\n\n|" \
+	    -e 's|[@]NM_LIBEXECDIR[@]|$(nm_libexecdir)|g' \
+	    -e 's|[@]NM_PLUGINDIR[@]|$(nm_plugindir)|g' \
+	    -e 's|[@]CHARON[@]|$(charon)|' \
+	    <$(srcdir)/nm-strongswan-service.name.in \
+	    >$(DESTDIR)$(sysconfdir)/NetworkManager/VPN/nm-strongswan-service.name
+
+uninstall-hook:
+	 rm -f $(DESTDIR)$(sysconfdir)/NetworkManager/VPN/nm-strongswan-service.name
+
 nm-strongswan-service.name: $(srcdir)/nm-strongswan-service.name.in
 	$(AM_V_GEN) \
 	sed -e 's|[@]NM_LIBEXECDIR[@]|$(nm_libexecdir)|' \
+	    -e 's|[@]NM_PLUGINDIR[@]/|$(nm_plugindir_abs)|g' \
 	    -e 's|[@]CHARON[@]|$(charon)|' $< >$@
 
 EXTRA_DIST = \
@@ -25,7 +40,7 @@ EXTRA_DIST = \
     intltool-merge.in    \
     intltool-update.in
 
-CLEANFILES = $(nmvpnservice_DATA) $(appdata_DATA) *~
+CLEANFILES = $(appdata_DATA) *~
 DISTCLEANFILES = intltool-extract intltool-merge intltool-update
 
 ACLOCAL_AMFLAGS = -I m4