fixed Magic strings
Merge branch 'master' of https://github.com/cs2103aug2014-t17-2J/main
fixed the bug of not not displaying deadline tasks correctly
Merge branch 'master' of https://github.com/cs2103aug2014-t17-2J/main
improved comments
Merge branch 'master' of https://github.com/cs2103aug2014-t17-2J/main