Added quaternion and angle_vector methods.
Added quaternion and angle_vector methods.

wlevine/nmatrix,agisga/nmatrix,wlevine/nmatrix,janusnic/nmatrix,janusnic/nmatrix,wlevine/nmatrix,agisga/nmatrix,janusnic/nmatrix,janusnic/nmatrix,johnmarinelli/nmatrix,agisga/nmatrix,johnmarinelli/nmatrix,agisga/nmatrix,wlevine/nmatrix,johnmarinelli/nmatrix,johnmarinelli/nmatrix