title: is it possible to combine non-ARC and ARC project code?
body: <p>Is it possible to combine ARC and non-ARC projects? I haven't really tried it yet but this is the scenario:</p>
  
  <p>We have an old iOS project (non-ARC) with a tab controller. There is a tab from the tab controller that doesn't have any function or view yet.
  I am making a new project which is related to the old project, and I would like to have it use ARC, if it is possible to combine my new project with the old one and assign my new project's view to the tab.</p>