Provide some vars for use in template's targets.

These new vars are DESTDIR (by default XBPS_DESTDIR/pkgname-version),
SRCPKGDESTDIR (XBPS_DESTDIR/sourcepkg-version) and FILESDIR
(XBPS_TEMPLATESDIR/pkgname/files).

This simplifies packages that used them.

--HG--
extra : convert_revision : 287ea7128cb5df19870ca7aff0a3b8f99a11d63a

templates/util-linux-ng/template

@@ -30,10 +30,8 @@ post_configure()
 
 post_install()
 {
-	local destdir=$XBPS_DESTDIR/$pkgname-$version
-
 	# Move logger to /bin.
-	install -d -m 755 ${destdir}/bin
-	mv ${destdir}/usr/bin/logger ${destdir}/bin
-	mkdir -p ${destdir}/var/lib/hwclock
+	install -d -m 755 ${DESTDIR}/bin
+	mv ${DESTDIR}/usr/bin/logger ${DESTDIR}/bin
+	mkdir -p ${DESTDIR}/var/lib/hwclock
 }