Filter/Group the pins on the Venues map

[nworbnhoj]

Currently all qwikgame venues are plotted onto the map - rather than just the venues within the map zoom area. This needs to be refined so that the VenuesPage.php scales properly from both a JSON data transfer perspective - and from a UI clutter perspective

[nworbnhoj]

Step 1. Map bounds

• limit the pins returned to those within the Map bounds
• respond to a change [](event) on the Map element and make a JSON call to venue-map-data.php to update the pins for the new map bounds

Step 2. Pin consolidation

• Sort the pins within the Map bounds by the distance to the pins (3) closes neighbours, and consolidate the nearest neighbours. Repeat until the number of pins is reduced to an acceptable maximum (20)
• Back ground process: maintain for each venue the (3) closest neighbours. Possible algorithm: Connect new venue to 3 random neighbours - ask each neighbour if any of it's neighbours are closer - repeat. Refinement: ensure all 3 neighbours are separated by minimum 90deg to ensure a reasonable triangulation.

[nworbnhoj]

Step 1 completed with commit 12c473cebda4b7c783e91e869e6919f3605e4aff Step 2 completed with commit b61e1586a4731e6d966dc3da593155c38721082c