Add Support for NTSC-U

[CryZe]

Looks like @hallcristobal already did some work for this: https://github.com/CryZe/libtww/pull/14/files

[CryZe]

Instead of using fixed addresses we should be using the actual symbols and structs in the game. Those should be fairly stable across all the versions, so the debug menu should then just work across all of them.