clearsightstudio/ProMotion — pull request #269 by bitgangsta (2013-08-15 01:56:38+00:00)
Title: Back button support

Another small change to support a back button navigation item.

Use it as normal, passing `:back` as the side to `set_nav_bar_button`. For example:

```ruby
class BuddyAddScreen < PM::Screen

title "Add a Buddy"

def on_init
set_nav_bar_button :back, title: 'Back', style: :plain, action: :back
end
end
```