Should not include closed versions by default

[TheRedBull]

Once a version is closed, it should not allow new issues to be added unless it is reopened. The current functionality allows a closed version to be used as the default and new issues added on creation.

I suggest that, if this is the desired base functionality, that an additional setting be added to 'allow closed versions'. When the setting is enabled, closed versions are shown in the setting; otherwise, only open versions are shown.