add helper text for delete all
parseTaskVenue and parseTaskPerson able to take in reserve keywords
added test case to test for validkeywords
added validkeyword conditions to other methods
All functions are now able to take in reserved keywords
add helper text for mark as done
Merge branch 'vani's_branch' into linh-dev
Merge branch 'Stanley's_Branch' into linh-dev

Conflicts:
	.classpath
	src/todologApp/CommandView.java
	src/todologApp/Controller.java
refactor CommandView and use ClassLoader for loading resources
merge linh's branch into ben's