Finish the required AEG Data structure methods

[James-Oswald]

Finish implementation of the methods described in #3. Rewrite other parts as necessary to make this work.
NOTE. ive removed the requirement that you pass in the xy coordinate the AEG is being moved to, you may assume the bounding box or bounding ellipse contains this information.

• verify AEG: ensure all AEG children are inside their parents and do not overlap on same level. #52
• insert AEG: given a new AEG, place the new AEG into the tree at the correct location based on bounding boxes.
• canInsert AEG: given a new AEG, find out if you can legally insert here without overlapping any bounding boxes. #45

Please notify @DawnTheWitch when this is done so she can begin #31