Plot steering input over time for one or multiple replays

[R00dRallec]

This new script allows to plot the steering inputs over time of one or multiple replays. For me it helped see the difference between the fishy replays and the ones considered legit, without having to watch videos etc.

Example:

Comparing riolu vs TMshock on map Desert C2:

Implementation is heavily based on existing script 'average_steer_partitions.py'.

Added dependency: matplotlib