Command for changing priority of a task

[rohanpm]

kobo should provide a command for resetting the priority of an already-scheduled task. The use-case is to adjust the relative priorities of tasks so that desired tasks are executed first, when the queue is full.

We already have "create-task". Suggestion: this should be a new "modify-tasks" counterpart. Only certain fields of a task could be modified; initially, at least the priority.

Example:

Usage: <command> modify-tasks task_id [task_id...]

Options:
  --priority=PRIORITY     priority