Light temperature warning indicator for GPS timeout, API timeout, and API failure

src/pkjs/weather.js

@@ -1,7 +1,22 @@
+function weatherFailure() {
+    Pebble.sendAppMessage({ PKJS_TEMP_BAR_COUNT: -1 });
+}
+
 var xhrRequest = function (url, type, callback) {
     var xhr = new XMLHttpRequest();
+    xhr.timeout = 7500;
     xhr.onload = function () {
-        callback(this.responseText);
+        if (xhr.status === 200) {
+            callback(this.responseText);
+        } else {
+            weatherFailure();
+        }
+    };
+    xhr.onerror = function () {
+        weatherFailure();
+    };
+    xhr.ontimeout = function () {
+        weatherFailure();
     };
     xhr.open(type, url);
     xhr.send();
@@ -31,8 +46,8 @@ function locationSuccess(pos) {
 function getWeather() {
     navigator.geolocation.getCurrentPosition(
         locationSuccess,
-        null,
-        { timeout: 15000, maximumAge: 60000 }
+        weatherFailure,
+        { timeout: 7500, maximumAge: 60000 }
     );
 }