memlayer(2): fix memdraw signature
libmemdraw: fix fd leak in openmemsubfont and memory leak in freememsubfont
libdraw: don't deference nil display in freefont
aux/vga: rescale after loading new mode

Intel VBIOS seem to not update its state unless in graphical
mode, so set the scaling mode after loading new graphical mode.
add games/md to /sys/src/games/mkfile
zymq: lilu dallas, multicore

implement multiprocessor support.
merge
aux/vga: scale only if mode was set successfully