major changes

a navigation model has been introduced, it allow representing the nested pages as a flattened list usable by the QML
"views" are ported to Controls.Page (PageExt), each page will define a header that will contains its title and toolbar to control its content. a DefaultPageHeader is provided as a default design
Network address bar has been redesigned
Artist page as been reworked to integrate the new toolbar, the toolbar is placed below the header and will stick as the user scrolls down, it uses a system of double Scrollable (the outter scrollable controls the scrollable of the list/gridview) the binding is bi-directionnal, when the list/grid scrolls by itself, the outter scrollable viewport is adjusted automatically
medialibrary indexation progress is moved to the sidebar
a "preference" access button has been added to the sidebar
side panels autocollapse when space is scarce
side panels are now sized in dp rather than a ratio of the whole size