made amplitude option have units pA that is converted to uA/cm2 based on a new membrane_area option
made amplitude option have units pA that is converted to uA/cm2 based on a new membrane_area option

DynaSim/DynaSim,asoplata/DynaSim,DynaSim/DynaSim,kupiqu/DynaSim,asoplata/DynaSim,DynaSim/DynaSim,DynaSim/DynaSim,asoplata/DynaSim,asoplata/DynaSim,kupiqu/DynaSim,asoplata/DynaSim,kupiqu/DynaSim,DynaSim/DynaSim,kupiqu/DynaSim