Some people prefer the old ASCII art look and it's good to have a way
to confirm that the fallbacks still work right on systems that have a
functional framebuffer available. Add a loader_gfx loader.conf(5)
variable to disable the eager use of graphics for these use-cases.
While we're here, clean up the style in the area a little bit; the early
porting that I did to lualoader did a lot of redundant ~= nil that has
carried over into some of the later work. We can drop some of that, and
also re-organize some of these variables to improve readability.