set_parameter! for ParallelDynamicalSystem

[rusandris]

set_parameter! for ParallelDynamicalSystem is buggy, but easily fixable.

This is the discrete case, didn't check for continuous:

using DynamicalSystems
ds = Systems.henon()
pds = ParallelDynamicalSystem(ds,StateSpaceSet(rand(3,2)))
@which set_parameter!(pds,2,1.2) 

Here set_parameter! gets dispatched to the wrong method:
set_parameter!(ds::DynamicalSystem, index, value)
which only changes the parameter of the first system from pds.systems.

There is a method for ParallelDiscreteTimeDynamicalSystem

set_parameter!(pdtds::PDTDS) = for ds in pdtds.systems; set_parameter!(ds, args...); end

but that needs to be corrected for something like

set_parameter!(pdtds::PDTDS,index,value) = for ds in pdtds.systems; set_parameter!(ds, index,value); end

I'll make a small PR later.

[rusandris]

Find the relevant commit here .