Working for UKF rename.

Most of the text is wrong, but changed code to use the
renamed ScaledUnscentedKalmanFilter.

Checking in with bad text because I am in the process of changing
FilterPy to use a class for the sigma points to make it easier
to change the sigma point generation, leaving us with one
UKF class instead of several.

book_format.py

@@ -62,6 +62,12 @@ def numpy_precision(precision):
 	yield
 	np.set_printoptions(old)
 	
+@contextmanager
+def printoptions(*args, **kwargs):
+    original = np.get_printoptions()
+    np.set_printoptions(*args, **kwargs)
+    yield 
+    np.set_printoptions(**original)
 	
 def _decode_list(data):
     rv = []