Refactor code for faster perfomance

[amar-laksh]

The code has to be completely refactored to increase performance and responsiveness.

Ideas for increasing performance:

1. Changing always on face detection to burst-mode detection across intervals.
2. Changing face detection parameters
3. Changing code dealing with the pressing of keys
4. Write unit tests for the project.

[Ridhwanluthra]

I would like to work on this

[amar-laksh]

Clone the repository, create a new branch ( e.g. perf-testing ) and start to code ! This might be useful: http://docs.opencv.org/3.0-last-rst/