Get rid of the map file in SGFS

[Akasaka Ryuunosuke]

Essentially, join script2zx.py and sgfs.py together to keep track of files during script build.

Then adjust the file commands to keep the SGFS pointer (volume #, start sector, length) instead of the file name in the scene bytecode.

[Akasaka Ryuunosuke]

This will allow us not to store a map file (GAMEDAT_.C) on the disk, and eliminate the need of dedicating a whole memory page to it. Though while we aren't too low on memory, we can go along without this.