[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/12873] Test the good identifier in \phpbb\db\tools

We need to rename the index key because with the default prefix (phpbb_)
this key has a length of 31. And because we don't accept the keys longer
than 30 characters we should ensure that by default no key is longer than
30 characters.

PHPBB3-12873
[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/12693] Add a travis test that checks file permissions

PHPBB3-12693
[ticket/12693] Fix indentation

PHPBB3-12693
[ticket/12693] Check if the files have the right 644

And not only if they are executable.

PHPBB3-12693
[ticket/12693] Fix the permissions

PHPBB3-12693
[ticket/12693] Check if the are executable and not if they are 644

PHPBB3-12693
[ticket/12693] Check the persmissions of the owner

PHPBB3-12693
[ticket/12693] Remove the executable bit on icon_print.gif

PHPBB3-12693
[ticket/12693] Extract exceptions, bin/* must be executable

PHPBB3-12693
[ticket/12693] Fix the query for bin/*

PHPBB3-12693
[ticket/12693] Expand manually the wildcard

PHPBB3-12693
[ticket/12693] All the files in bin/ must be executable

PHPBB3-12693
[ticket/12693] Force the composer.phar to be executable

PHPBB3-12693
[ticket/12693] The files skipped list can not be empty

PHPBB3-12693