Track tilemap event handlers and unbind at destroy

[rashidkpc]

Closes #3763

Tracks when events are attached to elements and unbinds them at map.destroy() time.

[lukasolson]

Hmm... I get the following error when I try to create a tile map now (and nothing shows up on the map):

TypeError: Failed to execute 'removeChild' on 'Node': parameter 1 is not of type 'Node'.
at TypeError (native)
at o.Control.o.Class.extend.removeFrom (http://localhost:5601/bower_components/leaflet/dist/leaflet.js:9:11353)
at o.Map.include.removeControl (http://localhost:5601/bower_components/leaflet/dist/leaflet.js:9:11654)
at http://localhost:5601/components/vislib/visualizations/tile_map.js:638:15
at Array.forEach (native)
at TileMap.destroy (http://localhost:5601/components/vislib/visualizations/tile_map.js:637:19)
at http://localhost:5601/components/vislib/lib/handler/handler.js:206:17
at Array.forEach (native)
at Handler.destroy (http://localhost:5601/components/vislib/lib/handler/handler.js:204:19)
at Vis._runOnHandler (http://localhost:5601/components/vislib/vis.js:82:29)

[lukasolson]

LGTM!