DNU #wantSteps on method remove

[MarcusDenker]

Bug description
When removing a method from the method browser --> DNU as #wantSteps is send to a non-morph

1 implementors of #acceptVisitorNeverFinishes:
2 remove that method with cmd-x
3 see DNU

wantSteps should check if the model is a morph or a model?

[MarcusDenker]

Sadly this does not work:

wantsSteps
	"Return true if the model wants its view to be stepped.  For an open system window, we give the model to offer an opinion"

	^ isCollapsed not and: [ model isNotNil and: [ (model respondsTo: #wantsSteps) and: [model wantsSteps ] ] ]

as the deprecated method #wantsSteps in Object means the "model respondsTo: #wantsSteps" is always true

[hernanmd]

Since #wantsSteps is only a Morphic thing we could just ask if model is a Morph?

wantsSteps
	"Return true if the model wants its view to be stepped.  For an open system window, we give the model to offer an opinion"

	^ isCollapsed not and: [ model isNotNil and: [ model isMorph and: [ model wantsSteps ] ] ]

[jecisc]

This is not only on Morph but also Model