Make faster AbsolutePath drawer, and allow FixedCamera to work with Homographies

[aguscas]

New things:

• Draws the AbsolutePath over canvas and overlay with frame (works with None transformation, Homographies, and Translations)
• Allow FixedCamera to work with homographies doing a similar idea

TO DO:

1. After this, should we still have the Paths class? Or should we merge it with AbsolutePaths and have only one? Having two different classes that are so similar might be confusing for users. Also there are subtle differences (get_points_to_draw taking a TrackedObject instead of points, because I needed the absolute and/or relative coordinates in AbsolutePaths)