Unique boxes containing pinned kinds should be shared kinds

[brson]

Currently unique boxes containing pinned kinds are pinned kinds but Graydon says they are supposed to be shared. To make this change we have to make sure that unique boxes containing pinned kinds can't be copied. I don't fully understand yet.

[brson]

Same is true for vectors of pinned

[brson]

I reverted this at least temporarily. Currently no unique kinds raise pinned to shared because that makes copying rules very complicated. So I'm trying to make sure that resources can't be copied first, then once there are lots of working tests we can try to make them embeddable in uniques.

[marijnh]

This seems like a bad idea, and is (if I understand the reasoning behind it) better handled by the revised kind system.