TODO:

  * Port over and improve clusterview and it's opengl stuff. It should use k-means point and cluster, as well as
    the math library from kmeans (add a test to dist). Additionally, the point and cluster of the clusterview should
    inherit from k-means point and cluster so that it can use the algorithm correctly. All other aspects of point and
    cluster in the clusterview program can be kept.
  * See note in opengl_widget. Make it a static class.
  * Do the same thing you did for opengl_widget in mode_handlers, leave the MODE_HANDLERS constant global.
  * Port over all tests from clusterview except the math tests. Improve point tests to include weight.
  * Turn kmeans into a python package and import it here.
  * Add a property to the point called weight, which is set when you click edit point. It will give a popup that
    allows you to specify a point weight. DEFAULT WEIGHT IS 1
  * Use kmeans to do the stuff - strip down point x y to refer to it's kmeans parent.
  * Weighted cluster mean is rendered as a hollow circle and unweighted k-means mean is a x.
  * Saving should save the weights, load should load the weights.
  * Make the current context exception string in opengl widget a constant and use that instead.
  * Add typing to every function except setters and __XYZ__ functions (__init__ can still have typing)