Support XmlElementWrapper annotation

[cjnygard]

Need to add support for XmlElementWrapper annotation when handling collections of types without creating an intermediate class to hold the Collection<T> member.

[DavideStefanelli]

We also need this feature. In our project hyperjaxb3 created 18 tables with only a primary key column which makes no sense and didn't find a way to overcome this without manual editing of generated classes