Secured BuildOurOwnBabylonJSController actions
Call BuildOurOwnBabylonJS.exe once BuildOurOwnBabylonJSWinJSApp has been built

Note: whereas ourOwnBabylon.js is regenerated when F5 is pressed for BuildOurOwnBabylonJSServer, it's not when F5 is pressed for BuildOurOwnBabylonJSWinJSApp (you have to first build the app)
Refactoring loading message management, creation a new class to handle that (in a new project).