Cannot open the developer console
The Developer Console plugin manages to activate itself, as it adds a menu item at the end of the main menu (visible when opening a project and clicking the hamburger button top-right). The problem is the menu item does not do anything. It should open a window with the Python console.
We should fix this by refactoring the code which sets up the menu item. Instead of connecting to the "activate" signal in Console.add_menu_item we should connect the menu item to an action object which does the same.