Maniac: Get Save Info - Allow requests for save with a null or negative value to work

[Mimigris]

Player platform:

Windows, 64 bits continuous build of the Player.

Describe the issue in detail and how to reproduce it:

For some reason, the command Get Save Info from the Maniac Patch, unlike the commands Load and Save from the same patch, allows to get info from a save with a negative or null value (requesting info of Save00.lsd (0), Save-7.lsd (-7) or Save-754.lsd (-754) will work if a save is present for said file for example, while the commands Load and Save wouldn't work in said case), and currently the Player does not imitate this odd behaviour, since it's probably a bug and that it may not be worth to replicate. Concerning the formatting of how the saves are named in this range, the save 0 is called Save00.lsd, and for any negative value the save will be called Save-X.lsd (even for values between -9 and -1, while between 1 and 9 it would be Save0X.lsd).

[Mimigris]

Since it's an inconsistency that does not make sense and that is more a bug than anything (you cannot save or load files on these values, so you wouldn't be able to have a save stored there in any case normally), moving this to #1818