mark
Merge branch 'master' of https://github.com/cs2103aug2014-w09-2j/main
perform delete in the history list
Merge branch 'master' of https://github.com/cs2103aug2014-w09-2j/main
refactor msg in delete method
- storage
- executor
delete can detect the where the task is from.
refactor
Merge branch 'master' of https://github.com/cs2103aug2014-w09-2j/main