Added three new helpers to be used by packages requiring GTK+ and

by pango itself.

To be able to run those helpers once the package has been stowned
properly, another variable available for templates has been added:
"postinstall_helpers".

This accepts a list of template helper names, e.g:

postinstall_helpers="gtk-update-gdkpixbufloaders.sh gtk-update-immodules.sh".

Also rather than setting extract_cmd itself in pkgfs.sh when
extract_sufx=".zip", set it in the helper itself.

--HG--
extra : convert_revision : 0f55c35f201daf6ff2e6d18cc808d0a34d8f4ddf

helper-templates/pango-update-modules.sh

@@ -0,0 +1,16 @@
+#
+# This helper updates the pango modules file when the pango package
+# has been properly installed and stowned.
+#
+
+pango_query_modules_cmd=$PKGFS_MASTERDIR/bin/pango-querymodules
+pango_query_modules_db=$PKGFS_SYSCONFDIR/pango/pango.modules
+
+if [ -x $pango_query_modules_cmd -a -w $pango_query_modules_db ]; then
+	$pango_query_modules_cmd > $pango_query_modules_db
+	[ "$?" -eq 0 ] && \
+		echo "=> Updated Pango's $pango_query_modules_db modules file."
+fi
+
+unset pango_query_modules_cmd
+unset pango_query_modules_db