Dataview / Tabview objects and use matrix

[dbauszus-glx]

The relationship between dataviews and tabviews is hideously complex and wants to be reviewed in the future.

The problem is that an object can be both. A dataview can be with in tabview in which case the show method is activating the tabview.

In a first step we untangled the checkbox from the dataview. A dataview should only have a target element into which the dataview is rendered.

A checkbox to toggle the rendered should be generated where it is required. eg. In a location view, or in a dataview layer panel.

The data for a dataview maybe assigned as data property to a dataview object. The data maybe null or undefined. The data can be queried and may change after the dataview has been created. It must be possible to update the dataview data as well as to recreate a dataview with a changed configuration.