Add option to automatically resume failed chunks up to maxRetries times ...

...before failing the file in progress.

This small patch allows you to specify maxRetries in the options object which will retry a chunk (PUT) request that many times before causing the entire upload to fail.

In our use-case it adds resilience to uploads where the receiving server may restart services less-than-gracefully, but is useful in the case of a poor network connection combined with a small chunk size.

It obviously only affects chunked uploads.