1. StartTime and EndTime is added into task.
2. Improve interfaces of DB.
3. Improve DB to be stronger
4. Central controller is finished.
5. Example code about how to use controller following MVC is finished
6. Controller, XMLManager, TaskList are singleton
7. Bug fixing.
Merge pull request #8 from Cutton/Da

Da
Merge pull request #9 from hav/Da

Da