Tour javascript is loaded even when there is no active tours

Note: the affect version needs to be refined

Reproduction steps

1. Go to http://localhost:8080/xwiki/bin/view/Tour/
2. Edit all listed tours and uncheck "activate"
3. Go to any page with the browser debug tool opened
4. Check the network tab

Expected

No "tour" related http requests can be found

Actual

The following requests are made:

• http://localhost:8080/xwiki/bin/jsx/TourCode/TourJS?language=en&docVersion=1.1
• http://localhost:8080/xwiki/bin/get/TourCode/TourJson?xpage=plain&outputSyntax=plain&tourDoc=Main.WebHome

• http://localhost:8080/xwiki/webjars/wiki%3Axwiki/bootstrap-tour/0.12.0/js/bootstrap-tour.min.js?r=1

 
Also, if all the tours are loaded for a given user, there is no need to load them again.
 

Possible approaches:

1. very fine-grained and only load the js for a given page if at least one tour or one step of a tour targets the current page with the right action etc...
2. load the js everywhere as long as at least one tour is activated (not so great but a least the tour won't be loaded when it's strictly useless)