[Users] GetComponent error messages

Hello,

I have a comment on an error message from GetComponents.

After showing the below error message, GetComponents stopped. But maybe a user doesn't want to perform a clean checkout every time such a mismatch occurs. I suggest to change the error message so that it instructs the users to solve the problem (by manually checking out the new repository) and then rerun GetComponents. Even better, GetComponents could do something like renaming the old checkout "thorn" to "thorn.old" and checking out the new repository.

./GetComponents einsteintoolkit.th

Do you want to update all existing components? yes, no [no] : yes

Error: The URL for AEIThorns/TensorTypes has changed, please perform a clean checkout.

Cheers, Luca