Feature Request - New Variable Selection Annotations

[schutta]

In scheduling problems, you may want to select a start variable of task that is on the critical path, i.e., a task with the longest tail. Normally, this is reflected by the largest value in the domain of the start variable. Therefore, it would be handy to a search annotation that chooses the variable with the smallest largest value in its domain. Such an annotation could be called smallest_largest. Surely, there should also be an annotation with the symmetric version.

For instance, the solver Chuffed supports such variable selection strategy.