Merge pull request #140 from cs2103aug2014-w13-1c/jin/gui

Views for priority levels and completed tasks
Added time parsing and priority detection

- now the date format must be dd MMMM yyyy HH:mm
- can detect priority in string type (have to ask the Model on how to
implement priority)
Merge branch 'staging' into ryan/controller
Correctly passed priority to Model
Merge branch 'ryan/controller' of github.com:cs2103aug2014-w13-1c/main into jin/gui