Add a decorator to indicate that a callback runs entirely host-side and
does not rely on a connection to the target. This means it will be
invoked even if the target was detected to be unresponsive.
- Add "hard" parameter to TargetManager's reboot().
- Pass in context to TargetManager's reboot() and
verify_target_responsive() -- this is needed for signal dispatch.
- Call self.reboot() instead of self.target.reboot() when attempting a
reset for unresponsive targets inside TargetManager, in order to
ensure that appropriate signals are dispatched.
Expose the RebootPolicy as an attribute of the ExectionContext and ensure
that that the target is not automatically rebooted if the reboot
policy is set to "Never".
If a target error occurs, check whether the target is unresponsive. If
it is, attempt to hard reset it if possible, or gracefully terminate
execution if not.
