No way to validate customfields if their values are are only valid for the current IssueContext (Project/type)

Scenario:

• Set a value on an issue for a Version Custom Field
• Open edit screen.
• In another tab, move issue to a new project with this custom field still available. Version CF get cleaned and validated.
• Click on save on the edit page (original tab)

Outcome:
The issue now has a version from the old project set as the value of the cusomfield.

Reason:
The version customfield has no way of finding out the IssueContext (Project/Type) during its validation. All it can do do is validate that the number is a version id, it check to see if it is an id of the issue's project.

We need to extend the CustomFieldType API to pass in an IssueContext (or list of). If we do this, we break all customfields....