2.4.16 * Make default shortcuts avoidable from Firefox's built-in shortcuts. Now you can scroll Tree Style Tab's sidebar by Alt-Shift-Up, Alt-Shift-Down, Alt-Shift-PageUp, Alt-Shift-PageDown, Alt-Shift-Home, and Alt-Shift-End. * Shortcuts for "scroll sidebar by line" now scrolls for three lines on each time. * Pinned tabs are now impossible to be collapsed. Even if they are collapsed accidentaly, the operation is safely blocked. * "Close This Tree", "Close Descendant Tabs" and "Close Other Tabs except This Tree" now work again. (regression on 2.4.15) * Better styling of extra buttons on the new tab button in the "Metal" theme. * Update `de` locale (by sicherist, thanks!)