* Add new keyboard shortcut slots "Simulate Up/Down/Left/Right Key on Tree" and assign default shortcuts Alt-Shift-Up/Down/Left/Right. They provide both spatial focus move on faviconized tabs and collapse/expand tree like arrow keys on tree items.
* Add new keyboard shortcut slots "Collapse Tree or Focus to Parent Tab" and "Expand Tree or Focus to First Child Tab" to simulate Left/Right Arrow keys on tree items.
* Wheel scrolling on pinned tabs and keyboard shortcuts to scroll the tab bar with focused pinned tab now scroll regular tabs if the container of pinned tabs is not scrollable.
* Optimize operations to track updated overflow/underflow state.
* Better drag and drop of tabs/trees across windows: the tree structure is kept better, temporary group tabs are kept, and moved tabs are kept discarded.
* Move focus to the parent tab as configured, when a last child tab is closed after it was reopened.
* Reduce needless animation effects unexpectedly re-applied to tabs rendered while virtual scrolling.
* Fix unexpected classes on tabs in the sidebar which are left by misordered operations.
* Fix unexpected infinit loop (caused increasing of CPU usage and blocking of GC) triggered by extra tab contents above/below individual tab.
* Update `zh_CN` locale by [NightSharp](https://github.com/NightSharp). Thanks!
* Update `ru`, `de` and `en` locales by [vadcx](https://github.com/vadcx). Thanks!