The tensor classes do not yet implement semicolonDerivative()

[bdezonia]

The tensor classes have been undergoing accelerated development and in a few days will be much more complete. There will only be one thing missing from their implementations: semicolonDerivative(). I have not yet found a source for an algorithm that can compute this simply for cartesian tensors. This is going to take some investigation. Implement something for all the tensor class implementations when possible.

[bdezonia]

I have a single algorithm (TensorSemicolonDerivative) that should suffice in the long run. It has commented out code on how to approach for general tensors some day. It also defaults to calcing the comma derivative because all my tensor implementations are cartesian and embedded in euclidean space. We will want to complete the algorithm when we implement general tensors in curved spaces.