[sdo] Issue 118 - Creating wrapper objects for simple types

If I'm not mistaken, SDO 118 has already been resolved in JSR235. We've 
agreed that DataFactory.create(someSimpleType) must return a wrapper.

What's still missing, is a way for clients to know if a type is a wrapper.

Proposal: Type.isDataTypeWrapper(). This would return true for any type 
that has the special "value" property (including formally defined types in 
an XSD).

Please let me know if you have any comments or better alternatives?

Thanks,
Frank.