20 tasks in the app for tutorial on 29/10/2014
Merge branch 'master' into Joel

Conflicts:
	JOYTZ/src/GUI.java
Revert "refactor of Storage and Executor"

This reverts commit 885d4f0f295d744bb711f8645a11320b357f5c09.
Revert "analysing method for multiple search, multiple delete and multiple sort are implemented in Analyer, relevant modifications have been done to ExecutableCommand, StringFormat, TimeHandler and UserInput as well, more test cases had been included in TestAnalyzer"

This reverts commit 767cce9825879d6768b59f2fd4cf50aee0c811eb.
Revert "Fix some stuff in controller (but not all)"

This reverts commit fbced7771bae3ce5dd1913abea4324264bbe6173.
Done history of user commands
Merge branch 'Joel'