Variations should be assigned to a shuffled set of turtles. Otherwise, some combinations of variations (in case of multiple traits) are not created. E.g. If there are 2 traits with 2 variations with 50/50 distributions, then only 2 combinations are created: T1V1T2V1 and T1V2T2V2. By shuffling, the agent sets used to assign variations are not identical and other combinations T1V2T2V1 and T1V2T2V1 are also created. Major Bugfix.