- Added support for a nonlinear wizard; page 1 ("define AoI") branches in three pages (the options of the combo box), that will end up in the same page ("compilation of base data")
- The plugin icon only shows/hides the dock, without restarting anything
- The project layers are setup in the first page, and re-loaded when entered the first page/restarted the wizard (if they are not already loaded)
- force the user to start a "new project" (or load a previous one) in the beginning of the plugin
- reimplemented the "draw AoI" function, as follows:
              - the user draws the polygon and presses next to the page; the polygon is saved;
              - the user draws the polygon and presses back to the previous page; th polygon is discarded
- implemented clip of the project layers, using the AoI, based on the processing framework; the new layers are automatically added to the view, before entering the nex step;