TODO

Add map credits
Make zoom centered on mouse cursor not the screen center
Remove from queue the tiles which are not needed any more
Show tiles from another level in place of missing ones (if already loaded)
Scale (km/miles/nm)
Ruler
Display current coordinates (partial: ugly HUD on Tab added)
Grid?
Limit time spent on one frame (skip creation of textures?)
Configurable map layers/sources
Make thread pool and downloader be shared between all layers

Done

Load tiles starting from center
Add garbage collection
Update license notice in source files.
Show tile state
Smooth zoom