Add RFC4039 rapid commit support.
diff --git a/src/dhcp-common.c b/src/dhcp-common.c
index d9719d1..8ff0f0d 100644
--- a/src/dhcp-common.c
+++ b/src/dhcp-common.c
@@ -556,6 +556,7 @@
   { "nntp-server", 71, OT_ADDR_LIST }, 
   { "irc-server", 74, OT_ADDR_LIST }, 
   { "user-class", 77, 0 },
+  { "rapid-commit", 80, 0 },
   { "FQDN", 81, OT_INTERNAL },
   { "agent-id", 82, OT_INTERNAL },
   { "client-arch", 93, 2 | OT_DEC },