Support for java.util.Optional

[kukido]

Hi Nicolas,
I know that gwt-jackson is currently limited to the lowest version of jdk supported by gwt. Will you be open to having a separate branch with jdk8 code? I've added support for java.util.Optional to our internal codebase via serializers/deserializers, but would love to share it with the rest of the community either via forked version or by submitting a PR to nmore/gwt-jackson.
Cheers,
Andrey

[nmorel]

Hello,

I think it should work with the current config if you add your serializer/deserializer inside an extension like guava.
Inside the pom.xml of your maven artifact, you configure the jdk to 8 and gwt version to 2.8+ and it "should" work.