type hints to remove reflection warnings

Greetings,
I've added sufficient type hints to remove the reflection warnings for clj-aws-s3.  I believe this is the minimum set of type hints to remove the warnings.  I've tested with the subset of clj-aws-s3 functionality that I use, but I don't use the full set.  Specifically, I don't use the multipart upload functionality, nor do I use acls (I handle all the permissions downstream).

Thanks for a powerful, simple and elegant set of Clojure tools.
-Chris