- Remove the now-unnecessary connection chaining bits from imports and exports.

- Remove the now-unnecessary connection chaining bits from imports and exports.

- In related news, always drop the exports' and imports' connection refs when
  they're destroyed.

- class_connect was leaking its "caller" (compare: "handle lifetime") ref to
  the new export.  We're going to try without the leak for a while, see how
  it goes.

- Bulk descs now have import and export pointers, so that they can play nicely
  with recovery.

- Clean, informative console diagnostics for recovery cases.  (Hi, Terry!)

- Do the ldlm-hook i_m_g/i_m_p based on emptiness of the conn_list, since it's
  far too late by the time the __exit routines run.

- Put an ugly-but-serviceable UUID in the server's connection's remote_uuid.

- Remember that we can already have an export in req->rq_export upon entry to
  target_handle_connect, if the client and server are the same node, and
  therefore share a handle table.

- Get rid of class_signal_connection_failure, which was vestigial at best.

- Welcome back to the world of connection-sharing.

- Call the upcall like:
  /path/to/upcall $FAILED_IMPORT_UUID $FAILED_OBD_UUID $CONN_UUID