Allows other classes to change Table view to SearchView and AllView from PhantomController.
Edited CommandLineController to give input to a LogicFacade class
Debugged PhantomController not getting CommandLineController refrence.
added the commandExecutor
added the LogicFacade
added Stack class to Storage for undo and redo.
Added methods to Command.
Modified TaskList.
Merge remote-tracking branch 'origin/yongkai'
Merge remote-tracking branch 'origin/jiashun'
Merge remote-tracking branch 'origin/krystal'