[ticket/12503] All tests should extend \phpbb_test_case

PHPBB3-12503
[ticket/12486] Rename data provider to fix "Risky" from phpunit

PHPBB3-12486
[ticket/12486] Make assertion on the return to remove "Risky" from phpunit

PHPBB3-12486
[ticket/12504] Remove unused request object from avatar manager test

PHPBB3-12504
[ticket/12504] Use defined variables

PHPBB3-12504
[ticket/12504] Use local variables where possible

PHPBB3-12504
Merge pull request #2411 from nickvergessen/ticket/12503

[ticket/12503] Fix several errors in test suite
[ticket/12507] Add console command to purge the cache

PHPBB3-12507
[ticket/12507] Move the 'require' statement

PHPBB3-12507
Merge pull request #2416 from Nicofuma/ticket/12507

[ticket/12507] Add console command to purge the cache

* Nicofuma/ticket/12507:
  [ticket/12507] Move the 'require' statement
  [ticket/12507] Add console command to purge the cache
Merge pull request #2330 from Nicofuma/ticket/12421

[ticket/12421] Don't parse [attachment] tags if user can't view them

* Nicofuma/ticket/12421:
  [ticket/12421] Rebase and enable tests
  [ticket/12421] Don't parse [attachment] tags if user can't view them