The event handling changes take care of VagueLobster's segfaults on
startup for all renderers (vulkan will still be iffy depending on his
hardware: it dies on my GTX 965 M, probably due to memory and QF's
shadows). One nice side effect is it takes care of the broken CD audio
event handling (does anyone even care, though?).
I never liked it, but with C2x coming out, it's best to handle bools
properly. I haven't gone through all the uses of int as bool (I'll leave
that for fixing when I encounter them), but this gets QF working with
both c2x (really, gnu2x because of raw strings).
