PyDoc: include buffer access in examples, cleanup

Note that buffer access is possible, also minor mathutils test cleanup.

doc/python_api/examples/mathutils.Color.py

@@ -28,3 +28,6 @@ print("Color: {:d}, {:d}, {:d}".format(*(int(c) for c in (col * 255.0))))
 
 # This example prints the color as hexadecimal.
 print("Hexadecimal: {:02x}{:02x}{:02x}".format(int(col.r * 255), int(col.g * 255), int(col.b * 255)))
+
+# Direct buffer access is supported.
+print(memoryview(col).tobytes())

doc/python_api/examples/mathutils.Euler.py

@@ -30,3 +30,6 @@ vec.rotate(eul)
 mat_rot = eul.to_matrix()
 mat_loc = mathutils.Matrix.Translation((2.0, 3.0, 4.0))
 mat = mat_loc @ mat_rot.to_4x4()
+
+# Direct buffer access is supported.
+print(memoryview(eul).tobytes())

doc/python_api/examples/mathutils.Matrix.py

@@ -30,3 +30,6 @@ mat[0][0:3] = 0.0, 1.0, 2.0
 
 # Each item in a matrix is a vector so vector utility functions can be used.
 mat[0].xyz = 0.0, 1.0, 2.0
+
+# Direct buffer access is supported.
+print(memoryview(mat).tobytes())

doc/python_api/examples/mathutils.Quaternion.py

@@ -29,3 +29,6 @@ exp_avg = (quat_a.to_exponential_map() +
 quat_avg = mathutils.Quaternion(exp_avg)
 print("Average rotation:")
 print(quat_avg)
+
+# Direct buffer access is supported.
+print(memoryview(quat_avg).tobytes())

doc/python_api/examples/mathutils.Vector.py

@@ -53,3 +53,6 @@ vec.xyz = vec.zyx
 vec.xy = vec4d.zw
 vec.xyz = vec4d.wzz
 vec4d.wxyz = vec.yxyx
+
+# Direct buffer access is supported.
+raw_data = memoryview(vec).tobytes()