trying to debug generation of uinput key events

I am going to abandon this branch - I really don't
understand how uinput works.  The current behavior is
that key events aren't received by fbcons until 8 of
them (4 presses and 4 releases) have been generated,
which is not a useful behavior.

Instead, I'm going to use the UNBLANKSCREEN ioctl
to unblank the screen whenever a button event occurs.