This directory contains shared UI backend code shared between
the desktop version and the mobile version.

The backend code sits between the actual functionality, which
are implemented in core and qt-models, and the UI/QML which
are implemented in desktop-widgets and mobile-widgets.

The idea of backend is not to duplicate code, and at the same time
limit the UI and QML to only deal with real GUI.

The first implementations for backend are "export" and "diveplanner".