`dtreemap` is not repositioned when DOM is changed

[Youcef Mammar]

dtreemap is not repositioned when DOM is changed. It could be only a CSS issue.
Below is an example that illustrates it.

1. when some long text is inserted before the treemap is built
   
2. when the same long text is inserted after the treemap is built (ie DOM is modified after treemap is built)
   

To reproduce this:

require(["dojo/ready", "dojo/dom", "dojox/treemap/TreeMap",
        "dojo/store/Memory", "dojox/color/MeanColorModel", "dojo/_base/Color"],
        function(ready, dom, TreeMap, Memory, MeanColorModel, Color) {
            ready(function(){

                // example from documentation
                var dataStore = new Memory({idProperty: "label", data:
                    [
                { label: "France", sales: 500, profit: 50, region: "EU" },
                { label: "Germany", sales: 450, profit: 48, region: "EU" },
                { label: "UK", sales: 700, profit: 60, region: "EU" },
                { label: "USA", sales: 2000, profit: 250, region: "America" },
                { label: "Canada", sales: 600, profit: 30, region: "America" },
                { label: "Brazil", sales: 450, profit: 30, region: "America" },
                { label: "China", sales: 500, profit: 40, region: "Asia" },
                { label: "Japan", sales: 900, profit: 100, region: "Asia" }
                ]});
                var colorModel = new MeanColorModel(new Color(Color.named.red), new Color(Color.named.green));
                new TreeMap({store: dataStore,
                    areaAttr: "sales", colorAttr: "profit", groupAttrs: ["region"],
                    colorModel: colorModel }, dom.byId("treeMap"));

                // changing the upper part of the DOM
                var longText = "Lorem ipsum dolor sit ame..."
                setTimeout(function(){
                    document.getElementById("text").innerText = longText;
                }, 500)
            });
        });

<p id="text"></p>
<div>
    <div id="treeMap" style="width:600px;height:600px"></div>
</div>