Add parameters to web-widget

Issue For some web-applications, it would be nice to adjust their response based on more than lat & lng. For example, having access to the current heading, we could only show wind-stations in a list view that lay in front of us, or turn a map so it's relative to our current heading.

Request Add the following parameters, which are already calculated internally but not available as query-parameters in the web-view:

• ${hdg}: heading in degrees
• ${alt}: current GPS-altitude in m
• ${spd}: current groundspeed in km/h m/s
• ${zlv}: zoom level of map

I tried to order these from important to less important as per my view :-)

Thanks!