Fixed UT bug - adding noise inside of loop.

The noise covariance should only be added to P once it
is computed - it was being added inside the loop causing it
to be added 2n+1 times.
Added example, unit test fix.

I really think there is a problem with the scaled UT formulation
as it produces wacky results with the recommendations given
in the literature. Hence, the test currently fails.

Added canonical 'bearing only' example for UKF.
Rename of sigma points classes, added example.

Renamed the sigma point classes to something more reasonable.
What I was calling Wan Merle wasn't even invented by them.

Added example for the bearing only problem that is done
everywhere in the literature.