node editing a mask doesn't work

[Jakub Steiner]

When you set a mask or clipping mask on a group, the node editing tool is unable to edit the clipping/mask object. See the attached test case. Regular object on the left, group on the right.

Not only would I like the mask to be editable, I would love to node edit all the objects in the group AND the clipping mask along with it. A common case when designing icons is to use clipping mask to define the putline of an object and have blurred objects inside to define shading. When you need to alter the shape, you have to sometimes unapply clipping masks for multiple nested groups and the process becomes super confusing/impossible.

[Jakub Steiner (jimmac-redhat)]

test case for missing mask editing capabilities