[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/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
[ticket/11552] Display checkbox in forums list

PHPBB3-11552
[ticket/11552] Change breadcrumbs structure

PHPBB3-11552
[ticket/11552] Keep first nav row on same line

PHPBB3-11552
[ticket/11552] Tooltips for breadcrumbs

PHPBB3-11552
[ticket/11552] More breadcrumbs adjustments

PHPBB3-11552
[ticket/11552] Responsive menu

PHPBB3-11552
[ticket/11552] Limit width of linklists

Limit width of left/right aligned link lists

PHPBB3-11552
[ticket/11552] Hide other popups when menu is toggled

PHPBB3-11552