Add a curses-based console

[TellowKrinkle]

The current console flickers every time it's updated, while curses doesn't

Automatically falls back to the old console if curses isn't installed

[generalmimon]

Any volunteers to review this? Cc @GreyCat, @abitrolly, @ams-tschoening, @dgelessus, @LogicAndTrick

[abitrolly]

Pass. My relationship with curses and the way linux terminal works are far from ideal.

[ams-tschoening]

I don't have a properly set-up Linux test system at all, but tested the PR on Windows and things still work like before. So from that point I'm fine with merging. :-)

[abitrolly]

No review, but I guess I can still run this on Linux later. I thought that the curses is the only way to do "graphical" stuff in terminal. :>

If there is any value in previous implementation, maybe it is worth to describe the differences and add a tag. If maintaining both implementation will become a burden, there will be at least some arguments.

[generalmimon]

Hmm, this actually doesn't look nearly as hard to review as it once did...

Maybe I'll look into it someday.