Rename backButton to more generic clearButton.
Update back button stuff in SFPeoplePickerNavigationController to match SFCongressNavigationController. Make sure accessibility label exists.
Remove UINavigationBarBlueFlatBack image. We have tintColor and translucent = NO now. SFAppDelegate sets navigationbar.translucent to NO since the appearance proxy (used in SFCongressAppStyle) doesn't support that.
Set some alignmentRectInsets on backButtonImage to make it position better in the navbar.
Update UIIconsHamburger.