Segment map is not self-balancing.

[RobertDurfee]

Given the level of effort that it took just to get the segment map working without self-balancing, this hasn't been implemented yet. The plan is to use AVL-style self-balancing in the future. The current testing suite forcibly constructs trees in multiple ways so all tree arrangements should be correct no matter in what order operations are called.

Workarounds:

• The correctness of the segment map is not dependent on whether it is self-balancing or not. However, without self-balancing, the performance of operations is not the desired O(log n). In fact, my observations suggest the tree is typically linear in practice.