docs / clenup (no functional code changes)

- added API examples for mathutils.Color/Euler/Quaternion/Matrix.
- corrected own bad spelling matricies --> matrices.
- minor pep8 edits.
- update CMake ignore file list.

doc/python_api/examples/mathutils.Quaternion.py

@@ -1,3 +1,23 @@
 import mathutils
+import math
 
-# todo
+# a new rotation 90 degrees about the Y axis
+quat_a = mathutils.Quaternion((0.7071068, 0.0, 0.7071068, 0.0))
+
+# passing values to Quaternion's directly can be confusing so axis, angle
+# is supported for initializing too
+quat_b = mathutils.Quaternion((0.0, 1.0, 0.0), math.radians(90.0))
+
+print("Check quaternions match", quat_a == quat_b)
+
+# like matrices, quaternions can be multiplied to accumulate rotational values
+quat_a = mathutils.Quaternion((0.0, 1.0, 0.0), math.radians(90.0))
+quat_b = mathutils.Quaternion((0.0, 0.0, 1.0), math.radians(45.0))
+quat_out = quat_a * quat_b
+
+# print the quat, euler degrees for mear mortals and (axis, angle)
+print("Final Rotation:")
+print(quat_out)
+print("%.2f, %.2f, %.2f" % tuple(math.degrees(a) for a in quat_out.to_euler()))
+print("(%.2f, %.2f, %.2f), %.2f" % (quat_out.axis[:] +
+                                    (math.degrees(quat_out.angle), )))