Defining default properties for Object Types

[LearnCocos2D]

The Object Types dialog should have a way to add default properties. That way, when you assign an object a predefined Type it should automatically fill in those properties with the default values where they don't exist already.

If a property already exists it should not be changed, or the user could be asked whether he'd like the properties to be reset to the object type's default values.

[bjorn]

I think this is basically a duplicate of #365 and it is covered by pull request #877