Add licence information: CC0
Licence boilerplate for problems 01-10
Clearer problem statements for problems 01-10
Cleanup of problems 01-10
Cleanup of test cases for problems 01-10
Cleanup Problem 11
Cleanup Problem 12
Cleanup Problem 13
Cleanup Problem 14
Cleanup Problem 15
Cleanup Problem 16
Cleanup Problem 17
Cleanup Problem 18
Cleanup Problem 19
Handle a cornercase in Problem 17

Gracefully handle out of bound arguments.
Cleanup Problem 20
Cleanup Problem 21
Cleanup Problem 22
Cleanup Problem 23
Cleanup Problem 24