fix(runner) make sure handler is always called inside of a promise
fix(task) component#task shall respect the original promise, change sig/task to receive a task object that wrapped the promise, this is to make the promise as argument, can go through when.lift/when.try
chore(runner) fix coding styles
Merge pull request #164 from troopjs/fix/signal-and-task

Small fix for some event runners, and to refactor task method