Allow AtomCommonAttributes#otherAttributes and AtomCommonAttributesSimpleContent#otherAttributes to be lazy initialized.

I am using the Jackson provider to serialize an AtomText which extends AtomCommonAttributes.

For as simple input as:

return new AtomText("someValue");

I get:

{
  "otherAttributes" : {
  },
  "type" : "text",
  "value" : "someValue"
}

AtomCommonAttributes#otherAttributes is accessed as in the rest of the Atom* beans. Is it possible to allow the map to be lazily initialized when the AtomCommonAttributes#getOtherAttributes() method is called like in the rest?

I can see this is also relevant for the AtomCommonAttributesSimpleContent class, so updating the summary.

Thanks.