/*!
\page p_matrix44_affine_packed Matrix44AffinePacked

The \ref p_matrix44_affine "Matrix44Affine" class represents a 4x4 matrix with an implied fourth column.  For efficiency,
the matrix is represented as 4 \c VectorIntrinsic values.  So, the last column, even though it is not maintained, still
uses up memory.  Clearly for efficient calculations, this is the best strategy, but it does mean storing this data in
memory is not as efficient as it could be.

The \c Matrix44AffinePacked type provides an efficient storage mechanism for \c
Matrix44Affine.  The \c Matrix44AffinePacked type does not store the last column,
so it takes 3/4 the space of the \c Matrix44Affine type.  The \c Matrix44AffinePacked type
does not provide any operations; it is only intended as a way of storing \c Matrix44Affine's.
Users must convert the matrix back to a \c Matrix44Affine type before performing calculations.
    
*/
