Spice netlist reader: should read "M" terminals in DGS order.

For DMOS devices where S/D will not swap, it is important to read the terminals in the correct S/D assignment.
Right now, the Spice reader reads it S, G, D, B, but it should be D, G, S, B to be compatible with standard Spice.

Please also see the elaborate discussion here:
https://www.klayout.de/forum/discussion/2238/how-to-extract-transistor-in-parallel-topology-in-lvs#latest