atl / addtasklabel            Adds task labels

   Format:
      ;atl <task_name> <label_list>
               Adds a list of labels to the task
      ;atl <task_name>
               Empties the task's list of labels

   Notes:
      Axmud tasks have formal names like 'status_task' and 'locator_task'. Task
         labels are a convenient way of referring to tasks without having to
         type the whole name. For example, the Status task has the task labels
         'stat' and 'status' by default.

      <task_name> matches the task's formal name. <label_list> is a list of one
         or more labels, e.g. ';addtasklabel status_task stat status'
      If <task_name> aleady exists, the labels in <label_list> will be added to
         its existing list of labels.

      To reset a task's labels to the default list, use ';resettasklabel'.
      The operation will fail if <task_name> isn't a known task (i.e. hasn't
         been added to the task package list; all of Axmud's built-in tasks are
         already in the task package list.)
      The operation will also fail if any of the labels in <label_list> already
         exist (even if they correspond to a different task).
      Task label names must be no longer than 16 characters, and contain only
         A-Z, a-z, underlines and 0-9 (not the first character). Non-Latin
         alphabets are acceptable.

   User commands:
      atl / addtl / addlabel / addtasklabel
