[ticket/12384] Run Travis CI HHVM tests against MySQLi instead of MySQL.

HHVM MySQLi has been fixed and works for us now.

PHPBB3-12384
[ticket/12174] Update topic_attachment flag when a post is soft-deleted

https://tracker.phpbb.com/browse/PHPBB3-12174

PHPBB3-12174
[ticket/12174] Corrections

PHPBB3-12174
[ticket/12174] Revert the changes on $topic_update_array

PHPBB3-12174
[ticket/12174] Update sql query

PHPBB3-12174
[ticket/12174] Remove inline assignment

PHPBB3-12174
[ticket/12174] Update the conditions

PHPBB3-12174
[ticket/12174] Don't update the flag for a post without attachment

PHPBB3-12174
[ticket/12174] Remove $update_topic_attachments_flag

PHPBB3-12174
[ticket/12174] Coding style

PHPBB3-12174
[ticket/12561] Add "after" check to schema_generator for columns_add

PHPBB3-12561
[ticket/12561] Added test for "after"

PHPBB3-12561
[ticket/12561] Add check to see if "after" column actually exists

If not, just append to the end

PHPBB3-12561
[ticket/12561] Added tests for "after last", "after missing" and "empty"

Also removed tabs

PHPBB3-12561
[ticket/12561] Reworked tests by nickvergessen

PHPBB3-12561
[ticket/12582] Add script for strippping ICC profiles from images.

PHPBB3-12582
[ticket/12582] Overwrite inplace instead of creating _original files.

PHPBB3-12582
[ticket/12582] Run strip_icc_profiles.sh on Travis CI.

PHPBB3-12582
[ticket/12582] Change strip_icc_profiles.sh to only take a single file.

PHPBB3-12582
Merge branch 'ticket/12384' into ticket/12384-ascraeus

* ticket/12384:
  [ticket/12384] Run Travis CI HHVM tests against MySQLi instead of MySQL.