Add option for confirmation on item delete.

[brianreavis]

Right now it's really easy to accidentally delete items... in some cases this is great (tagging), in other cases this is bad.

[wmartins]

What is the best way to do that?

I think we have to create a function called onDelete (maybe just delete). This function will be called when deleteSelection is called (if the onDelete function exists). If returns true, the element is deleted.

This will allow to define custom delete functions.

[brianreavis]

I think that's a good, customizable way of doing it ("onDelete" handler). However, I think !== false would be a safer condition. This way it'd behave identically to how normal event handlers behave. Return false to cancel, otherwise go through with the action. Yeah?

[wmartins]

I agree!