CocoMUD client

On Linux with wxGTK3, when CocoMUD starts and displays the connection screen with the list of choices, if clicking on the Connect button, CocoMUD crashes and the window is closed with a few critical errors in the console, no clear traceback.

After some debugging, the problem has been identified: for some reason, when the Connect button is clicked, CocoMUD sends the Cancel/Close signal to the application. This signal is intercepted just after the call to ShowModal(). It can "naturally" happen in two situations:

• When the updater finds new updates, if we ask to install them, CocoMUD asks every window to close. This includes the connection screen, if it is still open.
• When pressing escape on the connection screen, or forcing it to close another way, CocoMUD should react by closing the window. This is a desired behavior.

What IS NOT a desired behavior is that the Connect button would send the Cancel/Close signal (5101). Very simple tests with custom dialogs, using ShowModal() and understanding why this specific signal is sent at this moment would maybe lead to some solution. It also explains why, once opened on a world, if a user selects File -> Open and chooses a new world, this world is never opened: the Cancel/Close signal is still sent.