Implement&test ListIntSortedList... Test output->
... List implementation is more straightforward than tree
    but much less efficient many comparisons needed to place

-> Test output shows that everything works well with identical
   results for Tree and List implementation.

$ java TestIntSortedList
Run tests on TreeIntSortedList:
add 7 to the list
add 9 to the list
add 7 to the list again!
print the list contents in order: 7, 7, 9
verbose test whether list contains 9:
	Result list does contain 9
extend list and print in order 1, 3, 7, 7, 8, 9, 9, 13, 13, 14, 18, 19, 21, 22, 22, 22, 23, 26, 27, 29, 29, 33, 34, 34, 35, 37, 37, 39, 41, 43, 44, 45, 49, 50, 50
verbose test whether list contains 19:
	Result list does contain 19
verbose test whether list contains 28:
	Result list does not contain 28

Re-Run the same tests on ListIntSortedList:
add 7 to the list
add 9 to the list
add 7 to the list again!
print the list contents in order: 7, 7, 9
verbose test whether list contains 9:
	Result list does contain 9
extend list and print in order 1, 3, 7, 7, 8, 9, 9, 13, 13, 14, 18, 19, 21, 22, 22, 22, 23, 26, 27, 29, 29, 33, 34, 34, 35, 37, 37, 39, 41, 43, 44, 45, 49, 50, 50
verbose test whether list contains 19:
	Result list does contain 19
verbose test whether list contains 28:
	Result list does not contain 28
write up 3.3