Resolves #1096, device width for iOS devices

When content is rendered inside frames, the wrong size classes were being applied for iOS devices.  Switching to use screen.width as part of the calculation resolves this.

Android devices already behave as expected.

src/core/js/device.js

@@ -17,7 +17,9 @@ define(function(require) {
         $('html').addClass("size-"+Adapt.device.screenSize);
     });
 
-    Adapt.device.screenWidth = $window.width();
+    Adapt.device.screenWidth = isAppleDevice()
+        ? screen.width
+        : window.innerWidth || $window.width();
 
     function checkScreenSize() {
 
@@ -34,7 +36,11 @@ define(function(require) {
     }
 
     var onWindowResize = _.debounce(function onScreenSizeChanged() {
-        Adapt.device.screenWidth = window.innerWidth || $window.width();
+
+        Adapt.device.screenWidth = isAppleDevice()
+            ? screen.width
+            : window.innerWidth || $window.width();
+
         var newScreenSize = checkScreenSize();
 
         if (newScreenSize !== Adapt.device.screenSize) {
@@ -45,7 +51,7 @@ define(function(require) {
             Adapt.trigger('device:changed', Adapt.device.screenSize);
         }
 
-	Adapt.trigger('device:resize', Adapt.device.screenWidth);
+	    Adapt.trigger('device:resize', Adapt.device.screenWidth);
 
     }, 100);
 
@@ -58,6 +64,10 @@ define(function(require) {
     // Bowser only checks against navigator.userAgent so if the OS is undefined, do a check on the navigator.platform
     if (OS == undefined) OS = getPlatform();
 
+    function isAppleDevice() {
+        return /iPad|iPhone|iPod/.test(navigator.userAgent) && !window.MSStream;
+    }
+
     function getPlatform() {
 
         var platform = navigator.platform;
@@ -71,7 +81,6 @@ define(function(require) {
         }
 
         return "PlatformUnknown";
-
     }
 
     function pixelDensity() {