[ticket/11924] Bring layout of events.md to one style

PHPBB3-11924
[ticket/11924] Add script to export events.md with wiki markup

PHPBB3-11924
[ticket/11924] Add version info of template events to events.md

PHPBB3-11924
[ticket/11924] Reduce unneccessary load

PHPBB3-11924
[ticket/11924] Add option to export php event list

PHPBB3-11924
[ticket/11924] Fix some minor issues with the php event docs

PHPBB3-11924
[ticket/11924] Remove duplicated code

PHPBB3-11924
[ticket/11936] Fix Avatar overflow issue in Notification window

PHPBB3-11936
[ticket/11936] Restyle the notification text (no underline/decoration)

PHPBB3-11936
[ticket/11936] Use "no_avatar.gif" if needed in Notification window
[ticket/11936] Add no_avatars to UCP list Notifications too

PHPBB3-11936
[ticket/11936] Remove "px" from html syntax

PHPBB3-11936
[ticket/11930] Use \phpbb\path_helper for avatar URLs

This will ensure that avatars still properly display on extension pages
supplied via app.php.

PHPBB3-11930
[ticket/11552] Viewport meta for mobile devices

PHPBB3-11552
[ticket/11552] Add link to responsive.css

Add link to responsive.css and blank responsive.css

PHPBB3-11552
[ticket/11552] Basic rules for wrappers and header

Basic rules for content wrapper, common block wrappers and header

PHPBB3-11552
[ticket/11552] Add .nojs or .hasjs to body

Add .nojs to body element, swap it to .hasjs when
JavaScript is enabled

PHPBB3-11552
[ticket/11552] Responsive breadcrumbs

PHPBB3-11552
[ticket/11552] Responsive forums list

PHPBB3-11552
[ticket/11552] Move breadcrumbs up

Remove spacing between navigation and breadcrumbs
Fix comments format in responsive.css

PHPBB3-11552