Remove a no longer necessary `impossible`
Make tests work with sandboxes
Fix GC statistics overflow
Reduce redundant 'specifically' clauses in errors
Update expected error messages for tests
Define Show instance for Vect via toList.
Merge pull request #1712 from Melvar/remove-impossible

Remove a no longer necessary `impossible`
Merge pull request #1755 from mattias-lundell/master

Make tests work with sandboxes and fix GC statistics overflow
Merge pull request #1761 from bmsherman/dontDupErrors

Reduce redundant 'specifically' clauses in errors
Merge pull request #1763 from ziman/show-vect

Define `Show` instance for `Vect` via `toList`