Save stats/last status during Nodes#load

We probably should just axe Node#last, as Node#stats contains all it
does and more.
However it would need changing web views and I'm too lazy for that right
now.

Perhaps Nodes/Node also needs some unique ID so two instances of Nodes
can be compared exactly. Right now copying the old stats relies on name
being identical, but can we trust name to be unique? Even with groups
support?