Prepare new maemo release

Ideally this commit should go on top of the v3.13 branch
since the release is based on the v3.13 code base.

Change-Id: If13cf87463c7a3f7a9c2c96c916c543c9d2ed1a5
diff --git a/debian/README.Debian b/debian/README.Debian
index 0be0e83..f322765 100644
--- a/debian/README.Debian
+++ b/debian/README.Debian
@@ -1,4 +1,4 @@
-rockbox 3.12.x for Maemo
+rockbox 3.13.x for Maemo
 --------------------------
 
 Rockbox for maemo technial preview release.