Right now we have
AllowFeatureBuildStep (builderID, builderTeam, featureID, featureDefID, step)
callin.

It is called when:
- feature is getting reclaimed (in this case step is a negative number)
- feature is getting repaired (refilled with metal) before being resurrected
(in this case step is a positive number)

But it is not called when the actual resurrection takes progress (resurrectProgress variable is changed). Actually no callin at all is called when it happens, so it is very difficult and requires complex hacks to detect when the unit starts resurrecting and how much each builder contributes to the resurrection progress.

So I propose that either:
- AllowFeatureBuildStep should be called in such case, with new parameter "resurrectStep"
- some new callin is created and it is called when the resurrection progresses.