Fix default values being ints.
Fix syntax error.
Fix squared_length failing with non np arrays.
Fix dot not working for lists.
Fix interpolate not handling lists
Move create_(xyz) into plane where they shouldve been!
Fix start and direction not handling lists
Rename start to position.

This is more in keeping with other classes.
Tests + import changes + new functionality.

Change numpy import to be np (import numpy as np).
Add quaternion.create_from_matrix.
Add MANY tests.
Cleanup many tests (more to follow).
Use np.sin, np.cos, etc.
Remove exception in quaternion.create_from_axis_rotation,
just normalise the vector ourself.
Remove assert in quaternion.rotation_axis, just return an
arbitrary axis.
Remove exception in matrix33.create_from_quaternion, normalise
the quaternion ourselves.
Change imports to be local using absolute_import.