Now resolves nicely, but generates C code that segfaults (tries to get the class of an Int
Made addon propertie function final, fixes cover addon properties
Fixed redefinition error, added a test
Damn tabs snuck by
Added error for properties that would need to add a field definition inside an extension
Code cleanup
Merge pull request #717 from shamanas/98x

Properties can now be defined in extensions as long as they require no hidden fields to be defined.