TODO
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* Cm should be (optionally) a distributed variable (for myeline). It could be done simply by a check
that Cm is in the equations (if Cm=None, then we use the distributed variable).
* Write examples, including point processes
* Think about point processes. Use the Synapses object?
* Domain decomposition?
* Morphology: adding morphologies (at least cylinders)?
* Find out and specify the underlying electrical circuit (compartments/half-compartments?)
* Check with what Neuron does
* One thing is missing the Morphology: the position of the current branch in the
  big matrix (Note: all other variables, length etc, are views on the big matrix,
  for the current branch).