Upgrade AWS sdk to 2.7.5
fix placeholder fake in IE8 & 9 that brokes group listing in user management - fixes #12525
Remove checks for safe mode and magic quotes

Both are removed from 5.4.0

Safe Mode: http://php.net/manual/en/features.safe-mode.php
> This feature has been DEPRECATED as of PHP 5.3.0 and REMOVED as of PHP 5.4.0.

Magic Quotes: http://php.net/manual/en/security.magicquotes.php
> This feature has been DEPRECATED as of PHP 5.3.0 and REMOVED as of PHP 5.4.0.
Merge pull request #12166 from helmutschneider/aws-2.7.5

Upgrade AWS sdk to 2.7.5. Fixes #12023
Merge pull request #12646 from owncloud/remove-safe-magic-quotes

Remove checks for safe mode and magic quotes
Merge pull request #12636 from owncloud/fix-ie9-placeholder

fix placeholder fake in IE8 & 9 that brokes group listing in user manage...
[tx-robot] updated from transifex
Add REST route for user & group management

First step of a somewhat testable user management. - I know, the JSON returns are in an ugly format but the JS expects it that way. So let's keep it that way until we have time to fix the JS in the future.