Servo actuators modeling

[aqreed]

Right now the control surfaces inputs have no delay (they go from 0 to 1 in no time). A transfer function for the actuators would be interesting to add, I have a branch where I propose a first idea.

As you can see in line 53, what I simply do is multiply the signal by (1 - exp(-deltat/tau)) to simulate a 1st order transfer function, previously modifying the input function to add the argument tau (line 16)

[aqreed]

Translated to English. @AlexS12 this is low priority, but maybe we can start to discuss whether we are going to create a new class for the actuators or we are going to integrate it in the input_generators functions as I did in my branch.

[gurkanctn]

two more options (probably less computation?):

1. moving average of a few samples
2. rate limiter