MSL electrical spice3 - status and further development

The Modelica Standard Library was improved by adding a package of a subset of SPICE3 models which are transformed to the Modelica language. This Spice3 library contains basic models, sources, and four semiconductor devices (diode, BJT, MOSFET level 1, resistor). Extensive tests showed the correctness of model characteristics at simple circuits. Further models already prepared will be added to the Spice3 Modelica Library later on.