Unfortunately this area is not standardized by POSIX. Linux uses an ioctl
which is not that bad, but I'd like to have a designated function. I'm not
sure if this facility is powerful enough and whether it should be improved.
Also note that I use a struct winsize as on Linux, but I use size_ts instead
for the heck of it. Perhaps I should use another name for the struct.
The console renderer now renders to a text buffer, which can be implemented
on any device, whether it's the VGA text buffer or a bitmap graphics device
with font rendering. This replaces the older code that could only render to
a VGA framebuffer and where the input parsing was tightly coupled with the
device rendering phase.
