GitLab

fix issues 648 677

Change target perm from target.perm to x.perm.others

Use as `pauseTask(taskName)`. They return boolean values to tell the developer if a timed task can be paused/resumed/cancelled properly.
A little bit of testing shows that pausing and then resuming may execute the task multiple times.

by separately handling immediate one-time cost and cost over time.

fix #635