[ComboTabBar] Correctly returns tabAt over tab icon
[GreaseMonkey] Fix coding style
[TabBar] Use contextMenuEvent instead of customContextMenu signals
[ComboTabBar] Correctly switch tabs when closing last tab in tabbar

Also remove custom logic for SelectPreviousTab on tab remove and use
only the QTabBar's selectionBehaviorOnRemove

Fix 1 for #1322
[TabBar] Show add tab button at correct position when there are no normal tabs

Fix 2 for #1322
Closes #1322
[ComboTabBar] Fixed pinned tabs being hidden when there are no normal tabs
[ComboTabBar] Draw tabbar base even when main tabbar is empty
[ComboTabBar] Correctly set QStyleOptionTab::position for tabs

This fixes rendering of OnlyOneTab with Bespin theme.
[Code] TabHelper: Rename m_pinnedTabBar to m_isPinnedTabBar

[ci skip]
[Build] Link to execinfo also with OpenBSD

[ci skip]
[ComboTabBar] Use initStyleOption workaround only for Bespin theme

It is needed only with Bespin.
With other themes, it actually makes it worse.
[HistoryTreeView] Rewrite HistoryView to use same logic as BookmarksTreeView

It also fixes issue that middle click on item opened the url in both
current and new tab
[SideBars] Don't override cursor on scrollbars in History/Bookmarks sidebars
[Build] Fixed build after last commit
[Windows] Load font.tff (if exists) and set it as default font

This is needed for N'ko translation as default Windows fonts
doesn't contain glyphs for N'ko language.

Closes #1223
Updated translation strings

[ci skip]
Pulled translations from Transifex
[Cookies] More options for 3rd party cookies
Updated translation strings
[WebPage] acceptNavigation emits a signal