[Windows] Use %APPDATA% for PROFILEDIR

Also show warning message when using deprecated config path ~/.qupzilla
[ComboTabBar] Fixed draw issues with Oxygen theme

Always draw a selected tab in paint event. If the tab is not active,
let's just move the selected tab outside the tabbar's rect
[BookmarksToolbar] Clear button's mouseouver state after closing menu
[ComboTabBar] Correctly set height of pinned tabbar

Both tabbars will now have the same height.
This commit fixes incorrect drawing of line under pinned tabs when
moving tabs with Oxygen theme.

Also removed unused maxVisiblePinnedTabs property
[SearchEngines] Correctly set DuckDuckGo as default engine