S3FS

@sherakama likewise with #38, this should not affect existing installs; this just prepares us to be able to use S3FS. Depending on order of operations, this may or may not merge cleanly with the simplesamlphp branch.

Please do not delete this branch after merging.

(@mistermarco FYI)
![disagree](http://www.quickmeme.com/img/77/7773af9770acea44e2c046c6284ec7d1533d53c8d4091919f012c3f1a9d9adc9.jpg)