CC-3928: Use liquidsoap to test whether file is playable on upload.

-done
-tests return value and output

airtime_mvc/application/models/StoredFile.php

@@ -886,9 +886,9 @@ Logging::log("getting media! - 2");
                 }
                 
                 // Check if file is playable
-                $command = sprintf("/usr/bin/airtime-liquidsoap -c 'output.dummy(audio_to_stereo(single(\"%s\")))' > /dev/null 2>&1", $audio_file);
+                $command = sprintf("/usr/bin/airtime-liquidsoap -c 'output.dummy(audio_to_stereo(single(\"%s\")))' 2>&1", $audio_file);
                 exec($command, $output, $rv);
-                if ($rv != 0) {
+                if ($rv != 0 || count($output) != 0) {
                     $result = array("code" => 110, "message" => "This file appears to be corrupted and will not be added to media library.");
                 }
                 else {