Refactor Neural Network in C++ (Video Tutorial)

This was a long overdue video. The past videos on the neural network implementation in C++ had a lot of issues. Plus I had to use it for a project which turned out to be useful however it forced me to do some changes which I wasn't able to keep track of. This refactoring video will address the following issues:

• Memory leaks
• Decomposition of different modules
• Minor improvements