Allow max number of selections in a Predefined Choice List or Predefined Tags field.

As as admin of Aha!, I need to be able to set up custom fields with several options that can be selected up to a limit, so that I give users more flexibility to select multiple options, but not so many that it becomes unmanageable.

For example, I am setting up a custom field called "Customer segment". I have a preconfigured list of choices based on the customer segments across my product portfolio that I want users to be able to select one or more of when a user creates an idea, initiative, or release. However, I want to limit the selection to up 3. Sometimes, multiple customer segments benefit from an idea/feature/release, and we want to be able to slice the data accordingly without being limited to only one. That said, I don't want to enable more than 3, because then there's the temptation for a product manager to selection too many customer segments where it becomes meaningless.

In some cases one customer segment is too few, and we are unable to show roadmaps based on customer segment (in a standardized way) without this feature.