Multiple levels of docking and nesting
Tear-off widgets and vertical title bar when docking left/right. (like Visual Studio)
Only a editors area, which means zones which are not editor type contents can’t drag into the main window area, vice versa.
The tool bar is also dockable.
* Mulitpule tool bars in single row.
* Audo hide tool bar buttons when not enough space.
* When mutliplue tool bar in one row and not enough space, can resize tool bar zone sizes manually.
* Tool bar can float.
* When tool bar floating, user can drag border of tool bar and resize tool bar buttons to different rows.
* Customize supported.
* Double click on the header of a docking tool bar, it'll float to last floating position and last floating size. Or double click title bar of floating tool bar zone, it'll dock to last docked row and position.
