Valid parameter ranges?

[tclose]

In the parameter elements of the component class interface, do we want to be able to specify valid parameter ranges?

<Parameter name="gbar" dimension="membrane_conductance">
    <LowerBound><Value units="S/cm^2">0.0</Value></LowerBound>
</Parameter>

[tclose]

Could also think about extending this concept (or leaving room at least) for constraints based on multiple parameters, such as tauRise < tauFall in conductance synapses