Return control to original script after including a custom script. Allows

more flexibility to add code to a page. If the original is to be completely
replaced, the custom script must explicitly exit.
Credit to Eloy.

lib/setup.php

@@ -450,8 +450,7 @@ $CFG->httpswwwroot = $CFG->wwwroot;
 /// Use a custom script replacement if one exists
     if (!empty($CFG->customscripts)) {
         if (($customscript = custom_script_path()) !== false) {
-            include ($customscript);
-            exit;
+            require ($customscript);
         }
     }