Bad commit

Way too many changes applied.
Diode
Diode Template Complete

Only the template, not the functionalities.
Diode class complete
parseCircuitElementChange

Modified the parseCircuitElement method of CircuitBuilder class so that
it has access to all lines of the netlist.
Created a circuit element model class
Created a diode model class
Finished the diode model class
CircuitBuilder constructor change

Constructor now reads lines starting with "." first, then parse the rest
of the circuit elements.
CircuitModel Builder