Optionally use internal-remote transfer instead of local-to-remote if possible

[kapitainsky]

this is why I said hash is the safest. Crypt remote does not support hashes at the moment. You have to decide yourself.

Here some discussion about this exact issue:

Can not use --track-renames when syncing to and from Crypt remotes?

I have an issue where if I try to sync with --track-renames between two crypt remotes then I get an error that "--track-renames ignored because the two remotes do not have a common hash". The sync works, but not with the feature I want, which I think is pretty important for use. Also I can run with --track-renames if I try between two non-crypt remotes Is this some sort of intended limitation or is there a way to work around it?