veyron/mgmt/lib/exec: move this into veyron/lib/exec and merge veyron/lib/config with it.

Change-Id: I8c5b2d1f1a4a9d3c48b6e76e1fe5e43c93416c0d
diff --git a/services/mgmt/node/impl/callback.go b/services/mgmt/node/impl/callback.go
index 92ddf6f..46dbc21 100644
--- a/services/mgmt/node/impl/callback.go
+++ b/services/mgmt/node/impl/callback.go
@@ -3,12 +3,12 @@
 import (
 	"time"
 
-	"veyron.io/veyron/veyron/services/mgmt/lib/exec"
-	"veyron.io/veyron/veyron/services/mgmt/node"
-
 	"veyron.io/veyron/veyron2/mgmt"
 	"veyron.io/veyron/veyron2/rt"
 	"veyron.io/veyron/veyron2/vlog"
+
+	"veyron.io/veyron/veyron/lib/exec"
+	"veyron.io/veyron/veyron/services/mgmt/node"
 )
 
 // InvokeCallback provides the parent node manager with the given name (which is