ENH: Conversion to Eigen continuation.
ENH: Update QuadProg to use Eigen classes.
PERF: Replace vnl with Eigen cholesky decomposition.
PERF: Provide custom allocation to ensure alignment

As documented on http://eigen.tuxfamily.org/dox-devel/group__TopicStlContainers.html

special care needs to be taken to ensure alignment in Eigen.
PERF: Fix items for consolidation of types

Attempting to move all types to Eigen
compatible types to avoid unnecessary
memory copying.
ENH: A milestone in refactoring where test pass

This is not an optimal code base, but the code
compiles and passes all the tests.
PERF: Removed vnl to enforce Eigen consistency.

By keeping a common memory model computaitons
become much more efficient, and the code is
easier to read.
PERF: Constant value matrix are initialized once
ENH: Convert std::vector to EigenVector for State.
STYLE: Unify typedef naming usage.

Several different alias to the same types were used
during refactoring.  Now that they are consistent,
it is cleaner style to remove those helper types.
STYLE: Use typedef to globally select precision.
STYLE: Make math usage consistent.

Improve the precision of the constant for PI.