Clarify the behavior of "audit.can-author-close-audit"

Summary:
Ref T13631. This option has a behavior other than the behavior implied by the name and documented.

Document the correct behavior, at least. This can likely be removed after T10574.

Test Plan: Read config option help in Config.

Maniphest Tasks: T13631

Differential Revision: https://secure.phabricator.com/D21610

src/applications/diffusion/config/PhabricatorDiffusionConfigOptions.php

@@ -61,16 +61,22 @@ final class PhabricatorDiffusionConfigOptions
         ->setDescription(pht('Hard byte limit on including patches in email.')),
       $this->newOption('metamta.diffusion.time-limit', 'int', 60)
         ->setDescription(pht('Hard time limit on generating patches.')),
+
       $this->newOption(
         'audit.can-author-close-audit',
         'bool',
         false)
         ->setBoolOptions(
           array(
-            pht('Enable Closing Audits'),
+            pht('Enable Self-Accept'),
-            pht('Disable Closing Audits'),
+            pht('Disable Self-Accept'),
           ))
-        ->setDescription(pht('Controls whether Author can Close Audits.')),
+        ->setDescription(
+          pht(
+            'Allows the author of a commit to be an auditor and accept their '.
+            'own commits. Note that this behavior is different from the '.
+            'behavior implied by the name of the option: long ago, it did '.
+            'something else.')),
 
       $this->newOption('bugtraq.url', 'string', null)
         ->addExample('https://bugs.php.net/%BUGID%', pht('PHP bugs'))