Add the ability to add a tour without adding any skin extension object

Right now, to add a Tour in page, you have to:

1. edit that page
2. add a tour object on that page
3. add a JavaScript extension object and put some technical content there
4. add a CSS extension object and put some technical content there

In a ideal world, we should just add a tour object and that's all.

I think it's possible to do that.

1. Adding an UIExtensionPoint that will be displayed somewhere in the page. The location is not important, because this UIX won't display anything actually.
2. This UIX will look if there is any Tour in that page, and call the appropriate SSX and JSX.

Using the Sheet mechanism is not a solution because it can create conflict with other sheets if the page have other objects.