DockableToolbar now enumerates and adds support for adding a child view
DockableToolbar fix: Properly set widget parent
Build an example toolbar
Draw a crude black rectangle for our handle
Reduce padding
Steal some event tracking code from DockablePanel in order to make toolbars also dockable
Fix the handle color for toolbars.
Dockables should inherit the orientation of their parents.
Add a second toolbar button