Implement Connection.__del__, which is almost certainly going to trigger
more bugs down the line, because the state of the Connection instance is
not guranteed during __del__. Meanwhile, it is temporarily needed for
deployed-today Ansibles that have a buggy synchronize action that does
not call Connection.close().
A better approach to this would be to virtualize the guts of Connection,
and move its management to one central place where we can guarantee
resource destruction happens reliably, but that may entail another
Ansible monkey-patch to give us such a reliable hook.
Ansible's PluginLoader makes up bullshit when it imports a module
(mostly because it has to make up something), therefore we ended up with
duplicate copies of ansible_mitogen loaded: one under
ansible.plugins.*.mitogen, and one under the canonical namespace.
Which broke isinstance().
David Wilson