Return information about retries made

[psttf]

Hello and thank you for this library! Is it still maintained? I have the following suggestion:

Am I right that there is no way to know how many retries where made? This information is lost. I suppose it could be useful if retry functions return something like RetryStatus from Soostone/retry Haskell library.

[hwildwood]

This would be great, we also want to log how many retry attempts were made.