Adds default @ exclusions and doclet option `excludeAnnotationClasses'

Method parameters with jax-rs annotations @Context and @HeaderParam
are excluded from API docs. In addition the doclet option
`excludeAnnotationClasses' takes space-separated fully qualified class
names of other method parameters to exclude.

e.g. this resource with header-authenticated Bar injected

@GET
@Path("/foos")
public List<Foo> barsFoos(@Auth Bar bar)

Together with this javadoc plugin fragment:

<additionalparam>-excludeAnnotationClasses com.yammer.dropwizard.Auth</additionalparam>