final touches for labels

[x] size should depend on importance
[x] fix float inaccuracy wiggling by anchoring it to a tile and then compute a delta to the camera position
[x] link to wikipedia, if possible
[x] make phone number of huts callable on android
[x] pack address into one attribute field
[x] tickbox for webcams is not always working
[x] find a better symbol for the webcams and huts
[x] show hut name only when zoomed in, but always show symbol
[x] huts and webcams should be shown above ground similar to cities.
[ ] fine tune importance / visibility of cities and mountains.
[x] in top view, labels should be well above the terrain, otherwise they get occluded
[ ] Adlersruhe peak is missing -> should be shown when zoomed in -> LD: "just check adlersruhe is in osm dataset but it doesn't have any elevation stored -> we therefore aren't using this at all (fix would be to change the first query of peaks.sql where we are removing peaks that have no elevation set and give the importance_metric some value (e.g. 0)"
[x] Erzherzog Johann Huette is missing -> LD: "hm the adlersruhe hut is also present in the dataset but it is neither a planet_osm_point."tourism" = alpine_hut or wilderness_hut (not sure how it is classified)"
[ ] remove importance for webcams and huts -> LD: "this will most likely be done in the webcams.sql / cottages.sql"

AlpineMapsOrg / renderer