Single activity constructor accepts now String[]

also, related tests and then some more tests
now TextUiController can be slightly refactored

new SingleActivity(params[0], params[1], etc) becomes
new SingleActivity(params),
which surely looks nicer!
removing unused imports
javadoc for Parser
matchCommand makes more sense as a private method
"add weekly activity" command for textui
TDD: more tests for parser

* adding weekly activity
* failure case tests
new constructor for WeeklyActivity
more progress
more test cases
comments
command to view activities of specific week
implementing isInWeek() method
yet again, more progress to report
Merge branch 'better-text-ui'

Basic timetable-like functionalities implemented:
* adding activities
* viewing them