Old PD versions

[luap-pik]

I recently discovered that very old versions of PD.jl are still around in the package manager:

pkg> add PowerDyn...
PowerDynOperationPoint PowerDynBase            PowerDynamics           PowerDynSolve

@SabineAuer Is this intended?

[SabineAuer]

@luap-pik : yes, this is intended since some people still use these packages (e.g. from TU Delft) so we decided to keep them.

[luap-pik]

OK!