refactor add and delete methods into classes

Now there exists a Manager class for each type of class,
whose methods will be called depending on the action.
refractoring some of the magic numbers for UI component
test commit
replaced textarea with listview control
combine into single Task object
add description test
add description test
Merge branch 'master' into sun-taskclass
add more tests to Task
Merge branch 'sun-taskclass' of github.com:cs2103aug2014-w14-2j/main into sun-taskclass

Conflicts:
	test/application/TaskTest.java
extract TaskManager into own class with Javadocs
Created a new class : TaskListView (it is the customized version of the original Listview component).
removing redundant codes
Merge remote-tracking branch 'origin/sun-taskclass' into tys-ui

Conflicts:
	.classpath
	pom.xml
	src/application/Controller.java
	src/application/Task.java
	src/application/UiComponent.java
Format from tab to spaces.
added color variation for the square boxes
temporary initialization of arraylist

Fixes #62.
Removed all magic strings and magic numbers and added two methods for controller to update the listview data.
renaming of the public listview update methods.
Merge branch 'sun-taskclass'