[ticket/12325] Generate the list of the deleted files and folders

https://tracker.phpbb.com/browse/PHPBB3-12325

PHPBB3-12325
[ticket/12325] Add files located in deleted dirs

PHPBB3-12325
[ticket/12325] Add visibilities

PHPBB3-12325
[ticket/12325] Change private function to protected

PHPBB3-12325
[ticket/12325] Doc blocks

PHPBB3-12325
[ticket/12325] Use \RecursiveDirectoryIterator

PHPBB3-12325
Merge pull request #2410 from Nicofuma/ticket/12325

[ticket/12325] Generate the list of the deleted files and folders

* Nicofuma/ticket/12325:
  [ticket/12325] Use \RecursiveDirectoryIterator
  [ticket/12325] Doc blocks
  [ticket/12325] Change private function to protected
  [ticket/12325] Add visibilities
  [ticket/12325] Add files located in deleted dirs
  [ticket/12325] Generate the list of the deleted files and folders