Add onClick prop to floating panel

If panels are stored in array and have fix key, simply splice and push the clicked panel to bring it to front,
the newly pushed panel will have highest z-order.

src/jsx/panel.js

@@ -2,7 +2,14 @@
 var FloatingPanel = React.createClass({
   displayName: 'FloatingPanel',
   mixins: [Mixins.PanelWrapper],
-
+  propTypes: {
+    left:React.PropTypes.number,
+    top:React.PropTypes.number,
+    width:React.PropTypes.number,
+    style:React.PropTypes.object,
+    onClick:React.PropTypes.func,
+  },
+
   getDefaultProps: function () {
     return {
       "left": 0,
@@ -61,6 +68,12 @@ var FloatingPanel = React.createClass({
       this.setState({ left: left, top: top });
     }
   },
+
+  handleMouseClick: function (e) {
+    if (typeof this.props.onClick === "function") {
+      this.props.onClick(e);
+    }
+  },  
 
   render: function() {
     var transform = "translate3d(" + Utils.pixelsOf(this.state.left) + ", " + Utils.pixelsOf(this.state.top) + ", 0)",
@@ -94,7 +107,7 @@ var FloatingPanel = React.createClass({
       this.skipUpdate = false;
     }
 
-    return React.createElement("div", {style:wrapperStyle}, this.inner);
+    return React.createElement("div", {style:wrapperStyle, onClick:this.handleMouseClick}, this.inner);
   }
 
 });