add field promote to hook_node_info

Hi,

If I could make a wish it would be that the field promote would be settable in hook_node_info. This would allow module developers to set the default promote to true or false without having to do it every time the form is retrieved through hook_form_alter.

I think that many developers would like this option, I know that in my own modules I have done this often since I want my modules to work out of the box without any further settings that can be forgotten.