Investigate the Simulator class

[robbisg]

I used a trick to use the StateSimulator in Loader mode: usually a loader use fetch to load data from files and then uses some Transformers to process data, these classes use transform function which takes a dataset as input and outputs a transformed dataset, but basically the output of the first Transformer is the input of the second.
Leveraging on this mechanism, I used a StateSimulator that outputs the dynamics and the SimulationModel class then use this information to produce a dataset.

This thread is used to sketch ideas for a better implementation of this feature. (Related with #57 )

[robbisg]

I can use a base StateSimulator class which can be used to simulate states dynamics, then this can be used by another class that simulates the real signal.