WIP Eye Classification: Horizontal Edge image processing

The code is work in progress!
Will try to implement the proposed method in

http://web.yonsei.ac.kr/hgjung/Ho%20Gi%20Jung%20Homepage/Publications/2010/ICEIC2010%28An%20Edge-based%20Method%20to%20Classify%20Open%20and%20Closed%20Eyes%20for%20Monitoring%20Driver%E2%80%99s%20Drowsiness%29.pdf

Goals:
1. Implement horizontal edge image processing
2. Use horizontal edge image processing to extract feature(s) in order to train a classifier for open/closed eyes

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Commit:
* Adds a sub-package inside machine learning package.
* Renames old machine learning package to "initial".
* Adds a class that implements Horizontal Image Processing
  given an image.

Signed-off-by: Konstantinos Kostis <kekostis@gmail.com>