Support more than one clatd at a time.

The only change necessary is to stop calling the clat interface
"clat4" and instead name it based on the upstream interface
(specifically, "v4-<interface>".

Bug: 12111730
Change-Id: I489ebb0e3b1408ace8b64ca09ec20366fefe8d83
diff --git a/clatd.h b/clatd.h
index ca7369b..e7cef43 100644
--- a/clatd.h
+++ b/clatd.h
@@ -23,7 +23,7 @@
 
 #define MAXMTU 1500
 #define PACKETLEN (MAXMTU+sizeof(struct tun_pi))
-#define CLATD_VERSION "1.3"
+#define CLATD_VERSION "1.4"
 
 #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))