New random pulse generators added to control/pulsegen

In attempt to have a method of producing initial pulses that are random but less noisy,
so that final (optimised pulses) are also less noisy
Was also hoping that this would improve convergence rate
Two of the pulsegen are based on summing waves
Two are based on random walks
Bounds also added to the pulsegens, as the scaling / offset parameters could not be relied upon to effectively enforce bounds on all the new pulsegens.