[feature/plupload/deps] Adding parts of plupload_1_5_7.zip

PHPBB3-10929
[feature/plupload/deps] Add information about Plupload to AUTHORS.

PHPBB3-10929
[feature/plupload/cron] Add cronjob for cleaning plupload temporary directory.

PHPBB3-10929
[feature/plupload/cron] Namespacification

PHPBB3-10929
[feature/plupload/integration] Integration of Plupload

This commit is a highly-refactored and up-to-date version of Fyorl's work
which was part of his Google Summer of Code 2012 project "Attachment
Improvements".

PHPBB3-10929
[ticket/11913] Better download.phpbb.com directory structure for phpBB 3.1+

PHPBB3-11913
Merge pull request #1776 from bantu/ticket/11913

[ticket/11913] Better download.phpbb.com directory structure for phpBB 3...
[feature/plupload/integration] Add missing javascript file.

PHPBB3-10929
Merge pull request #1581 from bantu/feature/plupload/deps

[ticket/10929] Plupload dependencies
Merge pull request #1582 from bantu/feature/plupload/cron

[ticket/10929] Cron Job for Plupload Upload Directory Cleaning
Merge pull request #1772 from bantu/feature/plupload/integration

[ticket/10929] Integration of Plupload
[prep-release-3.1.0-a1] Update version to 3.1.0-a1
[prep-release-3.1.0-a1] Update changelog with 3.1.0-a1 changes
[prep-release-3.1.0-a1] Only build packages for the latest olympus versions
[ticket/11918] Make sql_freeresult() consistent across all DB drivers

PHPBB3-11918
[ticket/11919] Remove extra argument to notification manager's sql_fetchfield()

PHPBB3-11919
Merge remote-tracking branch 'noxwizard/ticket/11918' into prep-release-3.1.0-a1

* noxwizard/ticket/11918:
  [ticket/11918] Make sql_freeresult() consistent across all DB drivers
Merge remote-tracking branch 'noxwizard/ticket/11919' into prep-release-3.1.0-a1

* noxwizard/ticket/11919:
  [ticket/11919] Remove extra argument to notification manager's sql_fetchfield()
[prep-release-3.1.0-a1] Update changelog with the latest changes
[ticket/11920] Add MariaDB environment to Travis-CI.

PHPBB3-11920