Remember picked executable for subsequent launches

[MobyGamer]

Remember a user's launch choice for next time. For multiple executables in a title, prompt user "Remember this choice?" window title with more descriptive text in window body and a [Y]es [N]o. Create "default executable" flag and a means to store the default executable filename. This feature can likely piggyback on, or requires, #15 . Do not offer this dialog in KIOSK mode, but allow default choices to be honored in all modes.