[ticket/11031] Fix container construction and missing objects

PHPBB3-11031
[ticket/11031] Fix conversion of topic_replies to topic_posts

PHPBB3-11031
[ticket/11031] Update extension group names after converting them

PHPBB3-11031
[ticket/11031] Correctly set topic and post visibility

PHPBB3-11031
[ticket/11031] Fix missing variable lang_file from code conversion

PHPBB3-11031
[ticket/11031] Convert timezones to new 3.1 timezone

PHPBB3-11031
[ticket/11031] Fix group legend position

PHPBB3-11031
[ticket/11031] Correctly add groups to teampage

PHPBB3-11031
[ticket/11031] Convert user notification options with default settings

PHPBB3-11031
Merge pull request #1810 from nickvergessen/ticket/11031

Ticket/11031 Bring phpBB2 converter up to speed with 3.1 changes