Allow OpenSkyNetwork DB, OpenAIP and OurAirports DB stuctures to be
shared by different plugins, to speed up loading.
Perform map anti-aliasing on the whole map, rather than just info boxes,
to improve rendering speed when there are many items. Add map
multisampling as a preference.
Add plotting of airspaces, airports, navaids on Map feature.
Add support for polylines and polygons to be plotted on Map feature.
Add support for images to 2D Map feature.
Add distance and name filters to Map feature.
Filter map items when zoomed out or if off screen, to improve rendering
performance.
Add UK DAB, FM and AM transmitters to Map feature.
Use labelless maps for 2D transmit maps in Map feature (same as in ADS-B
demod).
Fix 3D map for Qt < 5.15.
Add 3D map label scale setting.
Add 3D map time to Web report.
Reduce height of display settings dialog to fit on smaller screens.
Add support for taken and predicted ground tracks.
Support multiple beacons with same callsign at different locations.
Use separate QML for Qt 5.14, as 5.12 doesn't support autoFadeIn, needed
to view satellites at min zoom.
Add support for different map types (street/satellite) and different map
providers.
Support finding real world addresses on the map.
Add Maidenhead locator converter.
Add Beacons.
Allow data sources to be selected by a user.
Add context menu to allow setting an object as a target, setting center
frequency and adjusting display order.
