ActivityID is overwritten with multiple resources on one processor

[hugostam]

Description

If a processor has multiple resources and various ships have a resource but the activities vary it is possible that the activityID of a processor is overwritten while it is processing.

Suppose a barge starts loading (activityID = loading) and during the env.timeout a second barge arrives. This second barge will be unloaded (activityID = unloading) and with the current setup it will overwrite processor.activityID. This will result in faulty logs.