DRT-3 Correlated Commits and PullRequests with tasks, even if the task has no work logged:
- updated SetUnfinishedTasks method;
- added TimeSpentOnTask property to Issue, that contains all time spent on a specific task (unlike TimeSpent that will only contain work logged just by one assignee);
- updated Template;
- Updated SetTasks method: deleted initialization of TimeSpent as it is set in SetIssue method;