version = planned 2015051100 release version
requires= current 2015050500 rc1 version
Note: On purpose, the course format social wrong version (2015102100)
has been kept unmodified. Looking forward a solution right now.
The native rename() function does not support moving folders
cross-device. See https://bugs.php.net/bug.php?id=54097 for details. So
instead of trying to move the whole tree, the new installer's method
moves files recursively one by one.
This is consistent with what mdeploy.php already does.