Make JacksonFeature configurable

[Deymus]

At present time there is no any possibility define witch modules would be registered in DefaultJacksonJaxbJsonProvider.
Current implementation of DefaultJacksonJaxbJsonProvider imports all modules(except JaxbAnnotationModule) founded in classpath. That leads to problem with unwanted modules would be registered. In example, we have jetty + jersey web server and we adding kafka to our application. Kafka has runtime dependencies to Jdk8 and Skala modules. Skala has jackson version check and any other modules can has it too. Its can create situation when auto registered 2 modules has non-overlapping version range check,wich cant be fixed by simple change jackson version.

My proposal to make registered modules in DefaultJacksonJaxbJsonProvider more configurable.
It can be achieved by

1. Make DefaultJacksonJaxbJsonProvider extendable with overriding findAndRegisterModules method
2. Make JacksonFeature configurable to replace registration of DefaultJacksonJaxbJsonProvider by customized one