Object Oriented Bounding Boxes

[BryonLewis]

• enables the rotate handle with a 'grab' icon for hovering style for rectangles
• adds function for calculating the rotation between rotated bounding boxes
• Stores the rotation value as a detection attribute called 'rotation'
• Added logic for reserved fields for detection and track attributes
• All bboxes should be stored as an axis-aligned bbox with a rotation in radians CCW about the center in radians
• If the rotation isn't default, a small arrow is drawn on the 'right' side of the bbox
• On modification I need to check the difference between rotating and resizing, there are helper functions to do that.