Description

The administrator shall be able to configure the content of the "mouse over" display in the TOC.
This shall be done for each TOC entry separately.
Currently it is the title; preferable it should be the title and description;

• Add an Advanced Options as switch panel in the layer settings.
  It is enabled by default and can be disabled by a flag (showAdvancedOptions = false)
• By default the switch panel is closed (expandedAdvancedOptions = false)
• In the switch panel there will be a combobox showing the property of the node that can be used to create the final tooltip. (title, description, both, none)