Default protocol implementations

[aleene]

Can I define some default protocol function implementations, so that I can get rid of the @obj and optionals.

[aleene]

I added this, but it was not very helpful. You still need to implement alls protocol functions, even if you do not need them.

[aleene]

It seems I have to get rid of datasource and delegate and call the functions directly. I can then overwrite specific functions in conforming classes. And I should make it an extension of protocol.

[aleene]

I will create separate files for Delegate and Datasource. And add a default implementation in an extension. IN apps that adhere I can override the implementations if required.

[aleene]

This seems to work.