Modified nest.{mz,mzi} to not require passing [x] at runtime.
Not yet updated the tests that depend on it.
Updated persistentarray_nesting.mz for the new nest API.
Removed some type applications that could be inferred.
Added nesting00, a test that fails with an internal error.
Updated queue_nesting.mz (which did not type-check; it was broken in
various ways, apparently). Now, it causes the type-checker to diverge
while slowly allocating more and more memory :-)