NavigationView.qml : Added the "title" property of the title of top view
Load QtQuick.Controls plugin
Refactor NavigationView.qml to use StackView
Added NavigationViewDelegate.qml for the transition effect of NavigationView
Added NavigationItem.qml and NavigationBarItem.qml(extracted from NavigationBar.qml)
Refactor NavigationView.qml : The type of "views" property has been changed to ListModel instead of array.
NavigationBar.qml : Supported to show page transition triggered by NavigationViews
Added NavigationBarTransition.qml to hold the transition effect for NavigationBar
mv NavigationViewDelegate NavigationViewTransition
NavigationBar.qml : The "navigationItem" property has been set correctly.
Added BarButtonItem.qml : For buttons placed on NavigationBar
Modified the parameters of transition animation for  NavigationBar and NavigationView
BarButtomItem : Change opacity on pressed
NavigationItem.qml : Supported to set the leftBar property
Merge branch 'master' of https://github.com/hilarycheng/quickios

Conflicts:
	QuickIOS/qmldir
NavigationBar.qml : Added tintColor property
NavigationBar.qml : Supported to place multiple button items
NavigationBarItem.qml : Added tintColor property and it will be set to NavigationBar.tintColor automatically
Added NavigationBarTitleAttributes.qml to set the colour of title
NavigationBar.qml : The back button has been changed to use BarButtonItem