Automatic disposal of old pack files

[danielga]

Possibly use date checking or just remove all pack files that are not pertinent to the current pack.

[danielga]

This is a problem with the current system. Files are downloaded by the engine and as such placed on the download folder, where you can't do anything. Even regular file opening of data files doesn't work since the DATA virtual path doesn't include download/data. No way to delete them with Lua.