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.Euler.py

@@ -1,3 +1,32 @@
 import mathutils
+import math
 
-# todo
+# create a new euler with default axis rotation order
+eul = mathutils.Euler((0.0, math.radians(45.0), 0.0), 'XYZ')
+
+# rotate the euler
+eul.rotate_axis(math.radians(10.0), 'Z')
+
+# you can access its components by attribute or index
+print("Euler X", eul.x)
+print("Euler Y", eul[1])
+print("Euler Z", eul[-1])
+
+# components of an existing euler can be set
+eul[:] = 1.0, 2.0, 3.0
+
+# components of an existing euler can use slice notation to get a tuple
+print("Values: %f, %f, %f" % eul[:])
+
+# the order can be set at any time too
+eul.order = 'ZYX'
+
+# eulers can be used to rotate vectors
+vec = mathutils.Vector((0.0, 0.0, 1.0))
+vec.rotate(eul)
+
+# often its useful to convert the euler into a matrix so it can be used as
+# transformations with more flexibility
+mat_rot = eul.to_matrix()
+mat_loc = mathutils.Matrix.Translation((2.0, 3.0, 4.0))
+mat = mat_loc * mat_rot.to_4x4()