STYLE: Remove outdated documentation.
ENH: Use Better tolerance for different slightly differnt results

Allow for upto a 10th of a point difference.
BUG: A new baseline image is needed.
ENH: use the Eigen template library for linear algebra operations

COMP: fix minor compile warnings
COMP: rename member variables in unscented kalman filter

COMP: move member variables that are really local temps out of class & into method

PERF: Reorganizing code to minimize computational burden

The QuadProg and unscented_kalman filters have many performance
bottle necks due to unnesary computations.

This patch reorganizes the code to make it a little more readalbe
and to add const correctness along with referenced variables wherever
possible.

STYLE: Code consolidation to prepare for performance improvements.
PERF: Testing intermediate changes for using Eigen

This patch demonstrates that both Eigen and the DoLittle LU solutions
produce very similar results, thus the next set of patches will replace
more of the vnl code with Eigen code.
PERF: Moving variables for better locality and less copying.
PERF: Avoid unnecessary matrix copies by using const references.
PERF: Move initialization of diagonal to class

The diagonal matrix could be initialized 1 time and used
many times by moving initializing it in the constructor.

Also converted from struct to class and add Eigen memory
alignment.