Add: Added function for saving slides.
Add: Added function for saving slides.

* Added function get_seed witch tries to find randomly good seed
  in the middle of a image.

* Added preprocesing function witch tries to pop up only green color
  by trying to thresholds image and then doing bitwise and on color
  channels.

* Added function write_image witch tries to crop the table and change
  perspective so even if the video is tilted or skewed we would get
  straight image and then tries to performe basic check with last image
  if it successed then it saves last image mask and last image as
  slide#count.png.

* Added function get_sorted_rectangle witch tries to sort edges of
  countures so we can use it for perspective warp.

* Added function get_croped_image witch tries to crop the only the table
  from image and warp its perspective so we would get table image as we
  would be standing in front of it.

* Added function check_change witch loads last slide and last image mask
  and perfroms bitwise and betweed mask of current image and mask of last
  image so we would get only mask with thing that are same on both pictures
  and then applies this new mask to old image and current image and tries to
  find keypoints and match them between images. If we match more than set
  similarity then the pictures are almost the same and we don't need to save
  else we save new image. This function for now returns True only for first
  image and then false because it still need tweeking and we would be saving
  a lot of data.

Foxiy/board2slides