#16 add RasterLayer to headlessmapProvider only if the layer is enabled and visible
Merge branch 'feature/16-export-map' into dev
#17 added the overview window to the default layout
#17 added the configuration of the OverviewComponent to defaultWatergisProperties.xml
#17 created AbstractShowHideWindowAction and ShowHideOverviewWindowAction
#17 added ShowHideOverviewWindowAction to Watergis menu
#17 added icon of ShowHideOverviewWindowAction
Merge branch 'feature/17-overview-window' into dev