update Radio Button behavior in Paper Toggle

This is for issue #73 the problem was that the onClick event of the
radio button associated to the toggle was triggered too, I removed the
onClick from the radio button associated to the toggle

src/js/toggle.jsx

@@ -36,10 +36,10 @@ var Toggle = React.createClass({
   },
 
   _onClick: function(e) {
+	if (this.refs.radioButton._onClick != null) this.refs.radioButton._onClick = null;
     var toggledState = !this.state.toggled;
 
     this.setState({ toggled: toggledState });
-    this.refs.radioButton.toggle();
 
     if (this.props.onToggle) this.props.onToggle(e, toggledState);
   }