amended singleton class usage, now can add successfully with singleton
updated command actions
Change taskList in StorageList to mainTaskList

variable name has been changed
Controller,UI and Executor has been integrated

Small integration on controller, UI and executor has been done
Merge pull request #26 from cs2103aug2014-t17-1j/Parser

Handling of invalid parameter without [] brackets.
Wrote a few test cases to test add. Adjusted indexOfStartParam to get first letter
Some changes on UiModifier and Controller class

UiViewModifier class creates controller object and then get the object
from the main and call the parser once the user add command
Sort by DueDate has been implemented in SummaryReport class

Sort by DueDate is done
Sort by Due Date is done and commented out some lines

Commented out some lines in commandActionClear
Spelling changed in task.java category

Category spelling wrong has been changed
displayList in SummaryReport has been changed

displayList in SummaryReport has been changed
Removed comments from Parser