Hello, are any of the following in the pipeline for Eigen's Quaternion class?:

- operator+, operator-, operator*scalar (quaternions should have these, if you disagree you are probably thinking of *unit* quaternions)
- toRotationVector (not angle-axis, the length is the angle. This might be the same as an exp function)
- fromRotationVector (might be the same as a ln function? ... but to/fromRotationVector is maybe clearer).

Thanks.