Deleting a link does not remove the associated TF frame

[gavanderhoorn]

Starting with a model loaded from disk (here lrmate200id.urdf):

Remove link_3. The geometry is correctly removed, and link_4 correctly reattached to link_2, but the TF frame remains (display of robot meshes was disabled for this screenshot):

expected behaviour: the frame link_3 should be removed as well and no longer show up in the visualiser.

[gavanderhoorn]

I've made this a minor issue as it's a visualisation thing more than anything else.

[gavanderhoorn]

A possible fix might be to register for linkDeletion and/or jointDeletion signals and call the appropriate method(s) on the URDFTransformer instance in URDFProperty.