edx/edx-platform — pull request #462 by cpennington (2013-07-22 17:30:44+00:00)
Title: Make XModuleDescriptor use the XBlock children API

N.B. When we are in a world of mixed XModules and XBlocks, the
system/runtime will have to be cognizant of that when asked to return a
XModule from an XModuleDescriptor child

[#LMS-190]

@ormsbee @sarina: Review?