Available since 3.0

The server might wait for the result of a call to disconnect_impl
which can now be delayed, that might cause a callback to never be
invoked and thus hang the driver thread.

To avoid that dispatch the disconnect_impl call from user process
instead of server.

It was broken.

Avoids spawn but can deadlock

Needed to avoid asserts when capturing mouse on Windows.

* maint:
  wx: Fix connect when terminating