Recommendation is to avoid using the year nomenclature as this
information is already encoded in the git repo. Avoids needing to
repeatly update.
Also updates AUTHORS.txt from current repo with contributor names
CHANGED abandon the unpredictable behaviour of the Simulation Command
dialog. You now separately add simulation tabs (which have invariant
command types once created), and the dialog edits the current tab.
Also a bunch of bug fixes to make multiple simulation plots actually
work.
SIMULATOR has now an Attach() method, which should be called
with proper SIMULATION_MODEL that should be simulated, before calling Run()
Concrete class of SIMULATION_MODEL for ngspice is NGSPICE_CIRCUIT_MODEL,
renamed from NETLIST_EXPORTER_PSPICE_SIM. DIALOG_SIM_SETTINGS relies
on above mentioned object, so it was added as an argument of the constructor.
