[ticket/11998] Add symfony/console as dependency.

PHPBB3-11998
[ticket/11998] Basic console application script.

PHPBB3-11998
[ticket/11998] Use container to get all commands using 'console.command' tag.

PHPBB3-11998
[ticket/11998] Also setup extension class loader.

PHPBB3-11998
[ticket/11998] Add console command for recalculating email hash.

PHPBB3-11998
[ticket/11998] Move application file to bin/phpbbcli.php

PHPBB3-11998
[ticket/11998] Add phpBB abstraction for application and command.

PHPBB3-11998
[ticket/11998] Turn develop/extensions.php into console commands.

PHPBB3-11998
[ticket/11927] Correctly add new files on update

Currently we ignore language and style files when the directory where they
go to do not exist. However in 3.1 we introduce some new sub directories:
* language/en/email/short/
* styles/prosilver/theme/en/
So we need to change our check to look whether the language or style exist,
rather then the parent directory.

PHPBB3-11927
[ticket/11927] Add doc block to new function

PHPBB3-11927
[ticket/11927] Prefix function with phpbb_

PHPBB3-11927
Merge pull request #1853 from nickvergessen/ticket/11927

[ticket/11927] Correctly add new files on update
Merge pull request #1849 from bantu/ticket/11998

[ticket/11998] Introduction of the phpBB Console
[ticket/11998] Make phpbbcli executable and add shebang

PHPBB3-11998
Merge remote-tracking branch 'naderman/ticket/11998' into develop

* naderman/ticket/11998:
  [ticket/11998] Make phpbbcli executable and add shebang
[ticket/11472] Make prosilver's editor.js an asset used by all styles.

PHPBB3-11472
[ticket/11472] Make the color swatch configurable and fix it in subsilver2

PHPBB3-11472
[ticket/11472] Update the ACP user signature page.

PHPBB3-11472
[ticket/11472] Use {T_ASSETS_PATH}.

PHPBB3-11472
[ticket/11472] Expand palette cell links to the full block size.

PHPBB3-11472