[ticket/12448] Allow null as default value for columns

PHPBB3-12448
[ticket/12448] Fix null columns for postgres

PHPBB3-12448
[ticket/12448] Fix null columns for MS SQL

PHPBB3-12448
[ticket/12197] Fix several misleading FAQ entries

PHPBB3-12197
[ticket/12782] Use an interface for the phpbb event_dispatcher

PHPBB3-12782
[ticket/12782] Add doc block

PHPBB3-12782
[ticket/12786] Extend profilefield_base_migration.php class

If extensions authors will use profilefield_base_migration.php
class as base class for creation of CPFs, the class need to be
extended a bit.

At the moment there are two issues with it:

It does not create entries for PROFILE_FIELDS_LANG_TABLE
(as it can't know what fields to create).

The migration is not "cleaning" the DBMS after purging
the extension and leaves everything except the CPF column.

Adding profilefield_language_data

PHPBB3-12786
[ticket/12786] Add get_custom_field_id

Adding function to get CPFs ID

PHPBB3-12786
[ticket/12786] Add create_language_entries

Add function to create entries in PROFILE_FIELDS_LANG_TABLE

PHPBB3-12786
[ticket/12786] White spaces found

Removed some white spaces

PHPBB3-12786
[ticket/12786] Add clean_cpf_db_entries

Add function to clean the cpf fields entries

PHPBB3-12786
[ticket/12099] Add request argument to path_helper service

PHPBB3-12099
[ticket/12099] Correctly fix the path when performing AJAX requests

If the current request is a AJAX we need to fix the paths.
We need to get the root path based on the Referer, so we can use
the generated URLs in the template of the Referer. If we do not
generate the relative path based on the Referer, but based on the
currently requested URL, the generated URLs will not point to the
intended locations:
	Referer				desired URL			desired relative root path
	memberlist.php		faq.php				./
	memberlist.php		app.php/foo/bar		./
	app.php/foo			memberlist.php		../
	app.php/foo			app.php/fox			../
	app.php/foo/bar		memberlist.php		../../
	../page.php			memberlist.php		./phpBB/
	../sub/page.php		memberlist.php		./../phpBB/

PHPBB3-12099
[ticket/12099] Remove config again

PHPBB3-12099
[ticket/12099] Add unit tests for get_web_root_path_from_ajax_referer()

PHPBB3-12099
[ticket/12787] Use a parameter (_referer) instead of the Referer header

PHPBB3-12787
[ticket/12786] Some minor fixes of comments and function naming

PHPBB3-12786
[ticket/12786] Dixing a typo

Typos fixed

PHPBB3-12786
[ticket/12787] Fix the absolute board url

PHPBB3-12787
[ticket/12786] Some changes of the comments.

Comments and quotes

PHPBB3-12786

[ticket/12786]

PHPBB3-12786

Revert "[ticket/12786]"

This reverts commit 61a6647101731110f67689b109de953f7449b03e.