Improve simulation support

[dvc94ch]

• [x] port eispice to python3
• [ ] add python models for ideal parts
• [ ] add support ibis model
• [ ] generate testbenches (psu, input-vector)
• [ ] add biasing assertions/measurements (v, i, p)
• [ ] add assertions in time-domain
• [ ] add ac simulation to eispice
• [ ] add assertions in frequency-domain
• [ ] add CPL part models
• [ ] mixed signal simulation with pyhdl