edx/XBlock — pull request #256 by lukedmor (2014-11-05 23:00:57+00:00)
Title: XBlock error handing fix

The problem with my previous commit was in line 141 (now 142), calling `class_.name` when it should've been `class_.__name__`. Also added traceback for later use (for an update soon coming to [xblock-sdk #32](https://github.com/edx/xblock-sdk/pull/32)).