load
Load the layout of the Harbour from Preferences (aka the registry on Windows).
The Harbour must have a DockFactory, which creates Docks based on a dockID
.
If settings for an unknown dockID are found, they are silently ignored. e.g. If you have renamed a dockID, or if a dock has been removed from your application.
Return
true iff preferences were found. Consider adding docks in default positions if the result is false.