Issue #3281772 by mcdruid: Hide the "Only For Testing" package by default on the modules admin page

modules/simpletest/tests/system_null_version_test.info

@@ -1,5 +1,5 @@
 name = "System null version test"
 description = "Support module for testing with a null version."
-package = Testing
+package = Only For Testing
 core = 7.x
 hidden = FALSE

modules/simpletest/tests/system_requires_null_version_test.info

@@ -1,6 +1,6 @@
 name = "System requires null version test"
 description = "Support module for testing system_modules()."
-package = Testing
+package = Only For Testing
 core = 7.x
 version = VERSION
 hidden = FALSE

modules/system/system.admin.inc

@@ -935,6 +935,8 @@ function system_modules($form, $form_state = array()) {
       ),
       // Ensure that the "Core" package fieldset comes first.
       '#weight' => $package == 'Core' ? -10 : NULL,
+      // Hide this package unless we're running a test.
+      '#access' => !($package == 'Only For Testing' && !drupal_valid_test_ua()),
     );
   }