Without flush we would might be loosing some bytes in writing.
This is explicitly stated in https://doc.rust-lang.org/std/fs/struct.File.html.

Also adds more explicit error handling in state related code.

Also adds flush operation after writing to file.

There's a new rust stable version.

Allows better understanding of the message.

More standard support for the `BusComponent` interface.

Allows blargg's test ROM to pass.

Made sure that OAM DMA takes 160 cycles to process.

This is a way of controlling the bytes that have already been written by the DMA controller.

Clarifies the boot state handling.