		    First order tensor (Vector) toolbox
		    -----------------------------------

Inputs can be matrices but will be treated according to
the variable 'prefer_column_vectors' as a grouping of
first order tensors.

Vector Functions (3 elements)
-----------------------------
mag(v)      -- Returns the magnetude of the vector.
unit(v)     -- Unitize, returns a unit vector is the same direction as v.
cross(u,v)  -- Cross Product of u and v.
dot(u,v)    -- Dot Product of u and v.

Quaternions (4 elements, unit length)
-------------------------------------
unit(q)     -- Re-normalize q.
qmult(q1,q2)-- Quaternion multiple q1 and q2.
qchk(q)     -- Check for a valid quaternion.
q2e(q)      -- Converts q to an euler axis and an angle.
e2q(v,a)    -- Converts euler axis v and angle a to q.
e2dcm(v,a)  -- Converts a euler axis v and angle a 
                to a direction cosine matrix.
