cmd/geth, jsre, rpc: run all JS code on the event loop

Some JSRE methods (PrettyPrint, ToVal) bypassed the event loop. All
calls to the JS VM are now wrapped. In order to make this somewhat more
foolproof, the otto VM is now a local variable inside the event loop.

jsre/jsre_test.go

@@ -1,16 +1,15 @@
 package jsre
 
 import (
-	"github.com/robertkrimen/otto"
 	"io/ioutil"
 	"os"
 	"testing"
 	"time"
+
+	"github.com/robertkrimen/otto"
 )
 
-type testNativeObjectBinding struct {
-	toVal func(interface{}) otto.Value
-}
+type testNativeObjectBinding struct{}
 
 type msg struct {
 	Msg string
@@ -21,7 +20,8 @@ func (no *testNativeObjectBinding) TestMethod(call otto.FunctionCall) otto.Value
 	if err != nil {
 		return otto.UndefinedValue()
 	}
-	return no.toVal(&msg{m})
+	v, _ := call.Otto.ToValue(&msg{m})
+	return v
 }
 
 func TestExec(t *testing.T) {
@@ -74,7 +74,7 @@ func TestNatto(t *testing.T) {
 func TestBind(t *testing.T) {
 	jsre := New("/tmp")
 
-	jsre.Bind("no", &testNativeObjectBinding{jsre.ToVal})
+	jsre.Bind("no", &testNativeObjectBinding{})
 
 	val, err := jsre.Run(`no.TestMethod("testMsg")`)
 	if err != nil {