Works better with bmake

Previously if there was no text printed at startup, the cursor was
never drawn.

The built-in powerdown function will probably be at a different
address on different firmware versions, and it doesn't work properly
with our hijump/lojump shenanigans anyway.

This makes the Power button work again, but I still need to figure
out what else to change before shutting down so the next boot
doesn't go to the "Reset System Data" screen first.

Only the bottom 4 bits of this port are control bits for the
parallel port. The upper 4 are status bits for power, so if we're
constantly clearing them in our WiFiStation routines, we won't get
proper readings of the power button when it's pressed.