Add Mountain Wave Project layer
map-click-handler.js: split formatting and logic code
map-click-handler.js: prepare displaying more than airspace data only
map-click-handler.js: show mountain wave info
map.js: save visible layers by layer switcher, remember visible overlay layers
map-click-handler.js: show location info only for visible layers
map-click-handler: enable on tracking and user pages
map-click-handler: prevent pagescroll on click
map-click-handler.js: fix/work around race condition not removing nearest circle

The circle might not got destroyed if the user was clicking in a very short
sequence on the map due to the delayed removal after fadeOut. This removes
all circles before adding a new one, working around that race condition.