moving around solvers (via web gui) is counter-intuitive (or broken)

The web GUI gives me error messages that look untrue,
e.g., when I try to "link in hierarchy" a solver,
it says "there is already a solver named X in space Y"
but when I look at Y, there is not X.

Perhaps I have trouble understanding these concepts:
* "copying" vs. "linking" a solver
* "recycling" a solver
What is the semantics? What are the intended use cases?
(A copy can be distinguished from a link only in case of updates.
But is it at all possible to update a solver? I thought one can only upload a fresh version.)

For Termination, it would be enough to have the following:
* each benchmark has a type (possibly a set of types)
* each solver can handle a set of such types
* more fine-grained: for a solver, each configuration can handle a set of types

Hi, Johannes. I'm going to let Cesare reply to this one, but it will be a few days due to other tasks he has currently.
Aaron