veyron.io/wspr: switch principal from vom to vom2.

Change-Id: Ib9674e337891aedef4707a75b75a88b1263a0d18
diff --git a/services/wsprd/principal/principal.go b/services/wsprd/principal/principal.go
index ed33767..4c0b0de 100644
--- a/services/wsprd/principal/principal.go
+++ b/services/wsprd/principal/principal.go
@@ -38,7 +38,7 @@
 
 	"veyron.io/veyron/veyron2/security"
 	verror "veyron.io/veyron/veyron2/verror2"
-	"veyron.io/veyron/veyron2/vom"
+	"veyron.io/veyron/veyron2/vom2"
 )
 
 // permissions is a set of a permissions given to an app, containing the account
@@ -152,7 +152,14 @@
 	if err != nil {
 		return nil, err
 	}
-	if err := vom.NewDecoder(vr).Decode(&result.state); err != nil {
+
+	decoder, err := vom2.NewDecoder(vr)
+
+	if err != nil {
+		return nil, err
+	}
+
+	if err := decoder.Decode(&result.state); err != nil {
 		return nil, err
 	}
 	return result, nil
@@ -167,7 +174,13 @@
 	if err != nil {
 		return err
 	}
-	if err := vom.NewEncoder(swc).Encode(i.state); err != nil {
+
+	encoder, err := vom2.NewBinaryEncoder(swc)
+
+	if err != nil {
+		return err
+	}
+	if err := encoder.Encode(i.state); err != nil {
 		return err
 	}
 	return swc.Close()
diff --git a/services/wsprd/principal/principal_test.go b/services/wsprd/principal/principal_test.go
index 9737042..f27157e 100644
--- a/services/wsprd/principal/principal_test.go
+++ b/services/wsprd/principal/principal_test.go
@@ -9,7 +9,7 @@
 
 	"veyron.io/veyron/veyron2/security"
 	verror "veyron.io/veyron/veyron2/verror2"
-	"veyron.io/veyron/veyron2/vom"
+	"veyron.io/veyron/veyron2/vom2"
 )
 
 func accountBlessing(p security.Principal, name string) security.Blessings {
@@ -59,11 +59,24 @@
 	bOrigin := pOrigin.BlessingStore().Default()
 	// Validate the integrity of the bits.
 	buf := new(bytes.Buffer)
-	if err := vom.NewEncoder(buf).Encode(security.MarshalBlessings(bOrigin)); err != nil {
+
+	encoder, err := vom2.NewBinaryEncoder(buf)
+
+	if err != nil {
+		return err
+	}
+
+	if encoder.Encode(security.MarshalBlessings(bOrigin)); err != nil {
 		return err
 	}
 	var wire security.WireBlessings
-	if err := vom.NewDecoder(buf).Decode(&wire); err != nil {
+	decoder, err := vom2.NewDecoder(buf)
+
+	if err != nil {
+		return err
+	}
+
+	if err := decoder.Decode(&wire); err != nil {
 		return err
 	}
 	decoded, err := security.NewBlessings(wire)