Create Support For Native Request Signing

[ryber]

Is your feature request related to a problem? Please describe.
Create a support for native request signing. With built in support for AWS request signing but able to perform other algorithms as well

Describe the solution you'd like
Be able to sign a request either explicitly or by default through the config. The Signing method should be configurable and should allow consumers to provide a custom implementation. Out of the box provide a AWS signer without pulling in the AWS SDK at all.