CC-2950: Tell users if they are running an out-of-date version or not

Initial implementation.
- added some code in phone_home_stat to retrieve latest version from stat server
  and store result in db

- created new view helper VersionNotify.php, which queries and calculates version
  difference, then returns the necessary information in html to the view files

- created new javascript file versiontooltip.js, which sets up the qtip stuff so that
  when the version notification icon is clicked, a tooltip is displayed

utils/phone_home_stat.php

@@ -74,6 +74,18 @@ if(Application_Model_Preference::GetSupportFeedback() == '1'){
     $result = curl_exec($ch);
 }
 
+// Get latest version from stat server and store to db
+if(Application_Model_Preference::GetPlanLevel() == 'disabled'){
+    $url = 'http://stat-dev.sourcefabric.org/airtime_latest_version';
+    
+    $ch = curl_init();
+    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
+    curl_setopt($ch, CURLOPT_URL, $url);
+    $result = curl_exec($ch);
+    
+    Application_Model_Preference::SetLatestVersion($result);
+}
+
 /**
  * Ensures that the user is running this PHP script with root
  * permissions. If not running with root permissions, causes the