Merge branch 'develop-ascraeus' into develop

* develop-ascraeus:
  [ticket/13137] Create schema.json in build script
  [ticket/13137] Improve output of create_schema_files.php
  [ticket/13137] Add schema.json file to .gitignore
  [ticket/13137] Generate the schema when the schema.json file is not available
  [ticket/13137] Remove schema.json file

phpBB/develop/create_schema_files.php

@@ -57,4 +57,4 @@ $fp = fopen($schema_path . 'schema.json', 'wb');
 fwrite($fp, json_encode($schema_data, JSON_PRETTY_PRINT));
 fclose($fp);
 
-echo 'done';
+echo 'Successfully created schema file';