update_calculate_project_update_status(&$project_data, $available)
Calculates the current update status of a specific project.
This function is the heart of the update status feature. For each project it is invoked with, it first checks if the project has been flagged with a special status like "unsupported" or "insecure", or if the project node itself has been unpublished. In any of those cases, the project is marked with an error and the next project is considered.
If the project itself i