Proper hiding of status bar on iOS6

Previously, navigation bar would not be positioned to
(x=0,y=0) when status bar would be hidden in some
view controllers.
Don’t use loadView when loading from storyboard

Per Apple docs, loadView should not be overridden when loading
from a nib or a storyboard. So we move setup of activity indicator
to viewDidLoad instead. Also improve formatting of some long
lines for better readability.