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
The menu is now displayed inside window, even when window
is not in fullscreen.
It now also contains the most important actions in addition to copy of
top level menus.
