Call nsIEmbedBrowserChromeListener::OnLocationChanged with an exposable url

Previously we were calling nsIEmbedBrowserChromeListener::OnLocationChanged
with a raw internal url. The raw url might have contained e.g. wyciwyg
scheme.
Merge pull request #15 from rainemak/fixLocationChanged

Call nsIEmbedBrowserChromeListener::OnLocationChanged with an exposable url