Exclude resolved issues from warnings

[fschopp]

The generated ProjectPlan contains warnings about issues that, even though not contained in the saved search themselves, are the parent, subissue, or dependency of another issue that is. The rationale is that the project plan may be unreliable if it ignores these issues. For instance, if a dependency is unresolved but not included in the saved search (and thus is omitted from the project plan), then it is unknown when this dependency may finish (so ignoring it is unreliable).

However, some of these warnings are currently "false alarms". For instance, if a dependency is resolved, then ignoring it from the project plan is safe.

The project plan warnings should not contain false alarms.