Move to different assembler/linker

[freem]

I've only just now realized that vasm and vlink can't be used for commercial purposes (outside of Amiga 68K), making them hard to recommend to anyone who wants to do serious and/or commercial work.

For Z80, this is less of a problem, since a number of assemblers exist already. The tricky part is the 68K. I can't compile gcc cross chain on my upstairs Windows computer for some stupid reason, so that's out unless I dedicate a VM to it.

Most 68K solutions in the homebrew console dev community (read: Genesis/Mega Drive) tend to use an outdated, Windows-only piece of software. I would really like to avoid this, because having separate makefiles for Windows and Linux/whatever else is garbage. (Also, free software zealots will endlessly complain about having to use Wine, but I prefer my reason to not do this.)