veyron/tools/naming: get simulator scripts going again, fix a bug in sort_endpoints.go

- bit rot took out the simulator scripts
- there was a bug in the sort_endpoints code that didn't correctly
  sort endpoints by protocol in the absence of a specific ordering.

Change-Id: I17a4c082f1852baacef2155e3f620bf21cb5a1c4
diff --git a/tools/naming/simulator/driver.go b/tools/naming/simulator/driver.go
index 01685f9..410877d 100644
--- a/tools/naming/simulator/driver.go
+++ b/tools/naming/simulator/driver.go
@@ -20,6 +20,7 @@
 
 	"veyron.io/veyron/veyron/lib/expect"
 	"veyron.io/veyron/veyron/lib/modules"
+	_ "veyron.io/veyron/veyron/lib/modules/core"
 	_ "veyron.io/veyron/veyron/profiles"
 )