Corrections for PlasmaLinac.assemble_trackables() that calculates the linac nominal energy from the nominal energy gains of each plasma stage

[ben-c-2013]

No description provided.

[kyrsjo]

Finally I understand, the only real change here is removing

if self.nom_energy is None:
            if self.stage is not None:
                self.nom_energy = self.source.energy + self.num_stages * self.stage.nom_energy_gain
            else:
                self.nom_energy = self.source.energy

And doing the prints per-stage (however the prints of upramp/downramp is conflicting with #182).

Merge #182 first, then merge back here and fix here. Then OK to merge.

[ben-c-2013]

Finally I understand, the only real change here is removing

if self.nom_energy is None:
            if self.stage is not None:
                self.nom_energy = self.source.energy + self.num_stages * self.stage.nom_energy_gain
            else:
                self.nom_energy = self.source.energy

And doing the prints per-stage (however the prints of upramp/downramp is conflicting with #182).

Merge #182 first, then merge back here and fix here. Then OK to merge.

Done in commit b90a61c.