Finish roboRIO-side vision code

It all builds with --cpu=roborio now, and successfully starts listening
for data when run on my laptop. I think it should work...

Change-Id: I5cb107f61ad7a63b2e0926a92c3238893719c5f5
diff --git a/y2016/constants.h b/y2016/constants.h
index cf75ae4..e5bbc06 100644
--- a/y2016/constants.h
+++ b/y2016/constants.h
@@ -99,6 +99,8 @@
     ZeroingConstants zeroing;
   };
   Wrist wrist;
+
+  const char *vision_name;
 };
 
 // Creates (once) a Values instance for ::aos::network::GetTeamNumber() and