BFS Iterative using a queue.
BFS Iterative using parent pointer and NextInLevel calls
Moves the BFS algorithms into their own source and head for management.

Fixes up the precompiled header.
Adds additional tests for the zig zag tree problem and bfs.

Adds the zig zag tree algorithm
Missing file that was untracked. Unsure why.
Post order iterative traversal with a current and prev pointer.

Built as an adaptation of in order traversal so it was clear how they were related.