Register the TomTom addon prefix for waypoint comm

diff --git a/TomTom.lua b/TomTom.lua
index b3771db..3f7f842 100755
--- a/TomTom.lua
+++ b/TomTom.lua
@@ -143,6 +143,7 @@ function TomTom:Initialize(event, addon)

     self:RegisterEvent("PLAYER_LEAVING_WORLD")
     self:RegisterEvent("CHAT_MSG_ADDON")
+	RegisterAddonMessagePrefix("TOMTOM3")

     self:ReloadOptions()
     self:ReloadWaypoints()