debugged default sorting order (added method in SortedArrayList to call when task deadline is edited
edited TaskListTest.
Changed SortedArrayList to parameterised type.
Changed use of PriorityQueue to SortedArrayList for display in TaskList method
Changed TaskListTest accordingly.
modified show command in Logic to include showing by added date and showing by tags
missed out some changes for SortedArrayList to parameterised type from last commit.
(debugged) set attribute TaskType of RepeatedTask when constructor is called.