DockManager implementation steps:
Initial:
 - Open up two editor windows on app start
 - Initially DockManager has empty background
 - Dragging one editor window anywhere on the empty background docks the window
 - Dragging another editor window over the window shows the drop overlay and you can dock that window onto any side
   - Currently the overlay is always shown and will trigger on mouse move and not only mouse drag

Undock:
 - Dragging on a title of a docked window undocks it

Resize sliders
 - Add a button between docked windows
 - Allow the button to be dragged, and it will automatically resize separating widgets

TitleBar dock/undock move
 - Dragging a title bar will move the title bar button while the cursor is within the widget area
   - If there are other title bars this will allow you to reposition the title bar
   - If cursor leaves the title bar (or widget area?) close the window and start actual drag and drop operation

TitleBar dock/undock 
 - Releasing the dragged window anywhere not on editor will re-open the window at that location
 - Releasing the dragged window over the drop overlay will dock the window
 - Moving the dragged window over a title bar will temporarily dock the title bar and allow you to move it (as in first step)
   - If you release the mouse the window will then be permanently docked at that location

Polish TOOD:
 - Change cursor icon when window is dragged
 - Prevent docking if available size is less than 20 pixels, otherwise there might be some weirdness

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Other things to remember:
 - Possibly add a way to have hidden widgets in the EditorWidgetContainer (like side-bars that pop on mouse over in Visual Studio)
 - A way to persist window states
 - Also a way to reset all widgets to original locations