[ticket/12841] Allow extensions to position new config vars

PHPBB3-12841
[ticket/12841] Fix white space issues reported by sniffer

PHPBB3-12841
[ticket/12841] Add a tests for the new function

PHPBB3-12841
[ticket/12841] prefix function name with phpbb_

PHPBB3-12841
[ticket/12841] Update comments in tests making after default

PHPBB3-12841
[ticket/12841] Make config position default to after

PHPBB3-12841
[ticket/12886] Remove obsolete check for f_user_lock

The user shouldn't be able to unlock his own topic if he doesn't have m_lock
permissions. Also, the check for f_user_lock was never going to evaluate to
true due to the topic not being unlocked making it obsolete anyway.

PHPBB3-12886
[ticket/12937] Do not return false. Return null for get and array() for all.

PHPBB3-12937
[ticket/12738] Pass $this->config in content_visibility constructor

PHPBB3-12738
Merge pull request #2838 from dhruvgoel92/ticket/12738

[ticket/12738] Pass $this->config in content_visibility constructor

* dhruvgoel92/ticket/12738:
  [ticket/12738] Pass $this->config in content_visibility constructor
Merge branch 'develop-ascraeus' into develop

* develop-ascraeus:
  [ticket/12738] Pass $this->config in content_visibility constructor
Merge pull request #2822 from marc1706/ticket/12886

[ticket/12886] Remove obsolete check for f_user_lock

* marc1706/ticket/12886:
  [ticket/12886] Remove obsolete check for f_user_lock
Merge branch 'develop-ascraeus' into develop

* develop-ascraeus:
  [ticket/12886] Remove obsolete check for f_user_lock
[ticket/security-155] Cast the types of string values in the controller routes

SECURITY-155
Merge remote-tracking branch 'github-bantu/ticket/12937' into develop-ascraeus

* github-bantu/ticket/12937:
  [ticket/12937] Do not return false. Return null for get and array() for all.
Merge branch 'develop-ascraeus' into develop

* develop-ascraeus:
  [ticket/12937] Do not return false. Return null for get and array() for all.
[ticket/security-155] Fix spelling error in comment

SECURITY-155
Merge pull request #2841 from nickvergessen/ticket/security-155

[ticket/security-155] Cast the types of string values in the controller routes
Merge branch 'develop-ascraeus' into develop
Merge pull request #2724 from VSEphpbb/ticket/12841

[ticket/12841] Allow extensions to position new config vars

* VSEphpbb/ticket/12841:
  [ticket/12841] Make config position default to after
  [ticket/12841] Update comments in tests making after default
  [ticket/12841] prefix function name with phpbb_
  [ticket/12841] Add a tests for the new function
  [ticket/12841] Fix white space issues reported by sniffer
  [ticket/12841] Allow extensions to position new config vars