Netlist Subcircuit Naming Bug (AKA VLSIR #65)

[dan-fritchman]

The Hdl21 half of https://github.com/Vlsir/Vlsir/issues/65.

So:

• VLSIR netlisting probably needs a change; the "use periods as path separators" won't work, especially since the injection of literal parameters
• Hdl21 should also probably change? It generates many of those dot-separated paths, in attempt to allow unique naming among (Python) modules.