TASKMAN-25: Change the default date

* Remove the default duedate value in the template
TASKMAN-19: Improve the view of task panel

* Add icon
* Improve the text effect (small and gray)
* Improve alignment of bottom text
Merge pull request #20 from woshilapin/TASKMAN-25

TASKMAN-25: Change the default date
Merge pull request #21 from woshilapin/TASKMAN-19.2

TASKMAN-19: Improve the view of task panel