CC-2737: Show disk space used/space available/ disk quota enforcement

-modify airtime-check-system to return values instead of printing
 them directly
-add ability to view select airtime-check-system via web interface

airtime_mvc/application/views/scripts/systemstatus/get-log-file.phtml

@@ -0,0 +1 @@
+

airtime_mvc/application/views/scripts/systemstatus/index.phtml

@@ -0,0 +1,10 @@
+<?php foreach($this->status as $key=>$value): ?>
+    <?php list($desc, $status, $downloadLog) = $value;?>
+    <div>
+        <?php echo $desc; ?>
+        <?php echo $status; ?>
+        <?php if ($downloadLog): ?>
+            <a href="systemstatus/get-log-file/id/<?php echo $key ?>">Log file</a>
+        <?php endif; ?>
+    </div>
+<?php endforeach; ?>