Set of patches:
Introduce TabStackedWidget+ComboTabbar
[Windows] Fix enabling blur background in fullscreen
[ComboTabBar] Fix some issues with pinned tabs
[ComboTabBar] Don't use pointer to integer,
Implement TabStackedWidget::keyPressEvent() and fix changing tab by wheel event
Fix animation delay of dragged tab's buttons.
[ComboTabBar] Add themable scrollButtons
