The ansible_mitogen test suite takes over an hour when Ansible is not
accelerated by Mitogen. This change aims to reduce that by skipping
tests with a large number of iterations when the linear strategy is
chosen.
The tagged tests are intended to uncover Mitogen resource leaks. Since
Mitogen is not invoked when strategy=linear, the slight reduction in
test coverage is an acceptable trade off.
Reverts 49736b3a, large file copies can't avoid the RTT.
The parent stack must be blocked while FileService progresses, as unlike
the small file path, it does not make a snapshot of the (possibly
temporary) file passed by the action plug-in. So we need to keep that
file alive while the service runs.
Add a new integration test and a new soak test to cover both.
Alex Willmer