Replace @@missing@@ when source is missing (#838)

Author: TheoChevalier

app/classes/Transvision/ShowResults.php

@@ -394,7 +394,9 @@ public static function resultsTable($search_object, $search_results, $page)
             $meta_source = $meta_target = $meta_target2 = '';
 
             // If there is no source_string, display an error, otherwise display the string + meta links
-            if (! $source_string) {
+            if ($source_string == '@@missing@@') {
+                $source_string = '<em class="error">Warning: Source string is missing</em>';
+            } elseif (! $source_string) {
                 $source_string = '<em class="error">Warning: Source string is empty</em>';
             } else {
                 $meta_source = "

app/views/results_entities.php

@@ -134,7 +134,9 @@
     $error_message = ShowResults::buildErrorString($source_string, $target_string);
 
     // If there is no source_string, display an error, otherwise display the string + meta links
-    if (! $source_string) {
+    if ($source_string == '@@missing@@') {
+        $source_string = '<em class="error">Warning: Source string is missing</em>';
+    } elseif (! $source_string) {
         $source_string = '<em class="error">Warning: Source string is empty</em>';
     } else {
         $meta_source = "