Added metric-option to web-view
Added option to show values in metric system.
Metric = false; // true|false

Removed unused conversion from aircraftsToJson() at dump1090.c-file.
Tweaked distance calculation to use google map api.

	modified:   dump1090.c
	modified:   public_html/config.js
	modified:   public_html/gmap.html
	modified:   public_html/script.js