This change integrates the license key ui into the application and makes it necessary for the user to enter a correct
key. The check for a correct key is done on startup and whenever a project is loaded. The check for the key also
includes a check whether the location of the application has changed.
* implemented saving project settings force-refreshes the project if something has changed.
* when nothing has changed while editing the project settings, the project is not refreshed anymore.
* new project window is cleared now before it is displayed.
Manuel Dobusch