edx/edx-platform — pull request #1561 by cpennington (2013-10-31 18:19:24+00:00)
Title: Fix AssertionErrors that were raised when creation of an XModule failed

The ErrorDescriptor wasn't getting the appropriate xmodule_runtime set, and
thus immediately raising an AssertionError when we tried to retrieve and
_xmodule from it.

[LMS-1388[