Fixes starting a new game in Operation: Eco-Nightmare

Jamming an absolute Windows path into a filename is allowed on Linux,
however Windows isn't as forgiving.

It would be nice to preserve the full path of the saved file;
unfortunately the SaveFileManager API doesn't support subdirectories.
For now just keep the old pattern of [gameid]-[filename].txt.

Fixes save games in Operation: Eco-Nightmare

It's possible for games to request files that don't exist in the game
path, e.g. C:\WINDOWS\TX2SAVES. As such, the method needs to always
include the quirk files, regardless of whether the path exists.

Fixes loading save games in Operation: Eco-Nightmare

This is a holdover from the original code, where the cast members
were loaded as part of the Score. Cast is now per-movie, so all the
resources should be in the one place.

Required for e.g. Inscape games, where movie files contain more data
than could (at the time) fit into RAM. Removes a noticable wait when
switching movie files.

Fixes the loader in Star Trek TNG Episode Guide