Faster rotated rect mask

v1.9.3

• use faster version of creating rotated rect mask
• move tests to their own directory
• avoid deprecated np.float
• improve drawing of rect and ellipse outlines
• improve some docstrings

v1.9.2

• use both black and white dashed lines
• fit to d and not d**2
• add more dunders to init.py
• fix residual calculation broken in v1.9.1