DateFormat L10N (Task List view)

2nd phase of DateFormat Localization. (1st: https://github.com/spacecowboy/NotePad/pull/226 )
This pull request will fix DateFormat problem in task list.

![device-2013-01-15-023723](https://f.cloud.github.com/assets/867470/72028/7fd46d90-6000-11e2-89b2-46eeb5cbc51b.png)