Allow overriding translations without creating PhabricatorTranslation

Test Plan: Overridden '%d Detail(s)', verified that it was used.

Reviewers: epriestley

Reviewed By: epriestley

CC: aran, Korvin

Maniphest Tasks: T1139

Differential Revision: https://secure.phabricator.com/D2815

src/infrastructure/internationalization/PhabricatorEnglishTranslation.php

@@ -23,4 +23,10 @@ final class PhabricatorEnglishTranslation
     return 'English';
   }
 
+  public function getTranslations() {
+    return
+      PhabricatorEnv::getEnvConfig('translation.override') +
+      parent::getTranslations();
+  }
+
 }