DFS algorithm for pizza slicing

[LyashenkoGS]

Implement BFS algorithm to our problem and describe it in our's wiki. I would like to suggest use draw.io. See #7 for example

[seajer]

Algorithm should be changed to DFS

[LyashenkoGS]

@seajer - agreed
https://github.com/LyashenkoGS/GoogleHashCode2017/wiki/DFS-pizza-slicing-algorithm
A scratch of the DFS algorithm customization has been created. Feel free to leave comments.