WIP: LightningMarkers
ViewModel: small performance boost
Lightning Collection: increase limit, and sort by most recent
Leaflet MarkerCluster optimization

- Only use addBulkMarkers, for efficiency.

Also, remove unnecessary async tests
Fix Lightning#parse

- LightningCollection is calling parse as a static
  method on the prototype, so we can't
  try to call instance methods.
MarkerCluster optimization

- pre-compile cluster html template
Lightning icons by age