XML Parsing: Enum as Element Type

[geri-m]

In the current implementation, an enumeration is only support as XML-Attribut, but not as an Element. We should have enumerations also as elements.

Currently this kind of XMLs/PoJos can be parsed/serialized

<?xml version="1.0"?><any attributeEnum="ENUM_1" xmlns="http://www.w3.org/2005/Atom" />"

  public static class AnyTypeEnumAttributeOnly {
    @Key("@attributeEnum")
    public XmlEnumTest.AnyEnum attributeEnum;
  }`

These XMLs/PoJos causes an exception (no Standard constructor for primitiv type).

<?xml version="1.0"?><any xmlns="http://www.w3.org/2005/Atom"><elementEnum>ENUM_3</elementEnum></any>

  public static class AnyTypeEnumElementOnly {
    @Key
    public XmlEnumTest.AnyEnum elementEnum;
  }