GA of 1.5.0

Release candidate 5 of 1.5.0

Release candidate 3 of 1.5.0

Release candidate 2 of 1.5.0

Release candidate 1 of 1.5.0

GA of 1.4.3

Release candidate 2 of 1.4.3

Fix verifying default docker registry (vmware#8233) (vmware#8248)

The default docker registry has been changed from
registry.hub.docker.com to registry-1.docker.io
in PR#8140. Scenario test should also rectify the
URL.

(cherry picked from commit c8199af)

Workaround for concurrent exec issues (vmware#8098) (vmware#8101)

There are outstanding issues to address with concurrent exec. This work is
palliative rather than an actual fix.

Removes checking for "started" in the status string - we reliably see this
field not propagating to the property collector despite being logged as
set in the tether. This _only_ applies to execs at this time as that is
the only path calling task.State (via InspectTask).

Adds locking around dispatch of execs, with a timeout, to serialize that
initial dispatch path against a single container. If the timeout expires
it reverts to current behaviour and relies on concurrent modification and
retry.

(cherry picked from commit c99f021)