[ticket/12017] Remove IN_PHPBB defined check

PHPBB3-12017
[ticket/12017] Copy config/ dir so events work

PHPBB3-12017
[ticket/12017] Fix phpbb requirement in composer.json

PHPBB3-12017
Merge pull request #1872 from nickvergessen/ticket/12017

Ticket/12017 Extension tests are broken on current develop