Update to AWS SDK 1.8.11 and provide various functional improvements.
- Support arbitrary nesting of collection objects (i.e. Map and List).
- Cache converted values when accessed to skip reprocessing.
- Better support for JSON number and boolean types.
- Add _getLinkHref() method to ResourceInfo.
- Add unmarshaller tests.
- Update copyright.
[maven-release-plugin] prepare release aws-hal-client-java-1.2
[maven-release-plugin] prepare for next development iteration