#1207 - Redirect to openhab.app with an existing sitemap.

Add redirection logic so that users going to:

    http://localhost:8080/

will be correctly redirected to the openHAB Demo HTML Page.  This redirect includes an `index.html` file, in the `webapps/static` directory, that can be modified by the consumer to target a different interface.

NOTE: This change uses a Browser-redirect, instead of a Server-rewrite, since the `RewriteHandler` doesn't appear to rewrite the context from null to `/static/`  All openHAB servlets have hooked themselves into the root context handler (doh!), so the `DefaultHandler` (for content in the FS) doesn't get a shot at the request.

The implication is that it's difficult to serve up _other_ root-owned static content, like `/favicon.ico` for example.