- We need to only take the general direction of the gradient
and not the actual value (hence the division by sum of abs)
- We take new values even if the score is equal, it might get
us out of a dead lock
- When reducing the step size, we look at how much we overshoot
to get a better new step size
- If the gain was lower than 1%, we quit, but we still take the
new value
Signed-off-by: Sylvain Munaut <tnt@246tNt.com>