Support HTML5 geolocation for centering map

Fixes #12 by auto-centering map in the easiest way possible

gmap.html

@@ -150,6 +150,21 @@
         });
     }
 
+    function center_by_geolocation() {
+        if (navigator.geolocation) {
+            navigator.geolocation.getCurrentPosition(function(pos){
+                Map.setCenter(new google.maps.LatLng(
+                    pos.coords.latitude, pos.coords.longitude
+                ));
+            }, function() {
+                console.log('Geolocation error');
+            });
+        }
+        else {
+            console.log('Geolocation not supported')
+        }
+    }
+
     function initialize() {
         var mapOptions = {
             center: new google.maps.LatLng(CenterLat, CenterLon),
@@ -158,6 +173,9 @@
         };
         Map = new google.maps.Map(document.getElementById("map_canvas"), mapOptions);
 
+        /* Set center by geolocation if browser supports it */
+        center_by_geolocation();
+
         /* Setup our timer to poll from the server. */
         window.setInterval(function() {
             fetchData();