* Make CopyPartSource constructor private
... and make individual record accessors exported. This change allows
adding of additional record members to CopyPartSource without breaking
applications.
* Move high-level copyObject functions to CopyObject module
* Make copyObject use SourceInfo, DestinationInfo
... to allow supporting features like client-side and server-side
encryption subsequently.
- fix warnings in tests/LiveServer.hs
- Add full examples for presignedGetObjectUrl and
presignedPutObjectUrl
- Lower-case `*URL` API functions to `*Url` to adopt a Haskell naming
convention
Finishes and fixes#35, #36 and #37.