Implement a specialized widget for editing the synonyms and narrower terms

[tudorache]

A term cannot be at the same time a synonym and a narrower term. We need to provide a specialized form widget that will prevent a term from being synonym and narrower term at the same time. In the current iCAT, this is done using a radio-button, but other approaches that achieve the same goal are fine. Here is an example from the current iCAT:

The widget should also support the deletion of a term, marking it as an inclusion term, and deprecating a term.

[matthewhorridge]

I believe that this is just form configuration but would need to understand how this is modeled to be sure.