Process escape sequence in launch path

[Nutzzz]

One example would be to prompt the user, e.g., with the provided command-line "mame.exe {?}", the user would be prompted to enter a rom name.

EDIT: Now that there's a file browser, perhaps "mame.exe {%}" would allow the user to choose a file from the filesystem as a parameter. In this case you'd want it without an extension; maybe another symbol, e.g., {*} includes the extension. And we'd want to have a default rom path in the database for such uses. (I think we already covered that in the SQLite db).