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/e2fsprogs/template

@@ -30,9 +30,7 @@ Add_dependency run e2fsprogs-libs
 
 post_install()
 {
-	local destdir=$XBPS_DESTDIR/$pkgname-$version
-
 	# Move libraries to /lib.
-	install -d ${destdir}/lib
-	mv ${destdir}/usr/lib/lib* ${destdir}/lib
+	install -d ${DESTDIR}/lib
+	mv ${DESTDIR}/usr/lib/lib* ${DESTDIR}/lib
 }