show markers worked once, but not anymore :(
red/orange triangles as event markers
Had my difficulties with leaflet, sometimes the map would not be
pan-/zoomable, neither manually with the mouse nor by the method
'fitBounds'. Looks like a strange timing problem because in main.js,
adding the dummy line
  var a = 1
cured the issue. However, after deploying it to the demo server, it would
not work againg. Then I added the leaflet default boxZoom and dragging
explicity, this helped again.

Have to keep an eye on that, could be a serious time killer ...