Changes:
- Now handles all internal position data as (x,y).
Bugfixes:
- Some pose masking did not properly threshold confidences
- Masking of keypoints not tiled correctly to x,y locations
- Pixel units never applied properly to some features
- FPS feature not applied to some segmentation features
- Adjusted angle features to be "mathematicians" angle (0 heading forward, + counter-clockwise)