[AD] Joystick in setup program

["Chris La Mantia" <celamantia@xxxxxxxxxx>]

My joystick jitters a bit when centered; I believe this is common to many
joysticks.  In Setup, since the joystick is enabled, this causes focus to
jump around quite a bit (this is 3.9.37).  In addition, it seems that when
running Setup, the joystick may not be calibrated yet, which would cause
similar wierdness.

So we have two issues:
- Should we perhaps remove the install_joystick from main() in setup.c, and
move it to the joystick calibration function?

- Should we increase the dead zones used to calculate the d1 and d2 settings
for each axis?  My joystick doesn't jitter THAT much...

--Chris