Start work on savedata parser

[JayFoxRox]

This is a small parser for the savedata (tgfd.dat, 4056 bytes) and profile (*.sav, 84 bytes) files.

This work is incomplete and I'm uploading it as I don't have time to finish this at the moment. A handful of issues will be created after merge:

• The lap-times are not assigned to the correct track. There might be a different order for track besttimes (vs. unlocked / locked bits) as I wasn't able to find any obvious pattern. Testing was quite time consuming as I had to get a record for each track I wanted to identify. Note that all best times currently have an even index. The lap-times don't have a printable track name. The order is the same as the track list dumped by extract-data.
• There are unknown or unused sections.
• Dreamcast savegames are not supported.
• Podracer order has not been confirmed. I think I just wrote them down in the order of the menu.
• Track order (for unlocking) has not been confirmed. I believe I just wrote them down in the order of the menu.

I wrote this some months ago, but I believe N64 used 84 byte profiles too. At least I remember that N64, PC and DC are very similar. I think the major difference was how the highscore names were stored.

Closes #7 .