XBlock Fragments expect unicode strings, and fail on an assertion when
it isn't:
```
2013-11-14 07:55:50,774 ERROR 3788 [django.request] base.py:215 - Internal Server Error: /courses/TestU/TST101/now/courseware/41d55c576a574fde99319420228f7f88/5fef5794e34842f4a2d45ebcdeaa9a3a/
Traceback (most recent call last):
File "/edx/app/edxapp/venvs/edxapp/local/lib/python2.7/site-packages/django/core/handlers/base.py", line 111, in get_response
response = callback(request, *callback_args, **callback_kwargs)
File "/edx/app/edxapp/venvs/edxapp/local/lib/python2.7/site-packages/django/contrib/auth/decorators.py", line 20, in _wrapped_view
return view_func(request, *args, **kwargs)
File "/edx/app/edxapp/venvs/edxapp/local/lib/python2.7/site-packages/django/utils/decorators.py", line 91, in _wrapped_view
response = view_func(request, *args, **kwargs)
File "/edx/app/edxapp/venvs/edxapp/local/lib/python2.7/site-packages/django/views/decorators/cache.py", line 75, in _cache_controlled
response = viewfunc(request, *args, **kw)
File "/edx/app/edxapp/edx-platform/lms/djangoapps/courseware/views.py", line 407, in index
context['fragment'] = section_module.render('student_view')
File "/edx/app/edxapp/venvs/edxapp/src/xblock/xblock/core.py", line 156, in render
return self.runtime.render(self, view, context)
File "/edx/app/edxapp/edx-platform/common/lib/xmodule/xmodule/x_module.py", line 903, in render
return block.xmodule_runtime.render(to_render, view_name, context)
File "/edx/app/edxapp/venvs/edxapp/src/xblock/xblock/runtime.py", line 356, in render
frag = view_fn(context)
File "/edx/app/edxapp/edx-platform/common/lib/xmodule/xmodule/seq_module.py", line 77, in student_view
rendered_child = child.render('student_view', context)
File "/edx/app/edxapp/venvs/edxapp/src/xblock/xblock/core.py", line 156, in render
return self.runtime.render(self, view, context)
File "/edx/app/edxapp/edx-platform/common/lib/xmodule/xmodule/x_module.py", line 903, in render
return block.xmodule_runtime.render(to_render, view_name, context)
File "/edx/app/edxapp/venvs/edxapp/src/xblock/xblock/runtime.py", line 356, in render
frag = view_fn(context)
File "/edx/app/edxapp/edx-platform/common/lib/xmodule/xmodule/vertical_module.py", line 27, in student_view
rendered_child = child.render('student_view', context)
File "/edx/app/edxapp/venvs/edxapp/src/xblock/xblock/core.py", line 156, in render
return self.runtime.render(self, view, context)
File "/edx/app/edxapp/edx-platform/common/lib/xmodule/xmodule/x_module.py", line 903, in render
return block.xmodule_runtime.render(to_render, view_name, context)
File "/edx/app/edxapp/venvs/edxapp/src/xblock/xblock/runtime.py", line 356, in render
frag = view_fn(context)
File "/edx/app/edxapp/edx-platform/common/lib/xmodule/xmodule/x_module.py", line 464, in student_view
return Fragment(self.get_html())
File "/edx/app/edxapp/venvs/edxapp/src/xblock/xblock/fragment.py", line 34, in __init__
self.add_content(content)
File "/edx/app/edxapp/venvs/edxapp/src/xblock/xblock/fragment.py", line 71, in add_content
assert isinstance(content, unicode)
AssertionError
```
BY writing to stderr, BaseHTTPRequestHandler writes log messages to the
console during testing. This makes the output harder to interpret.
Write the log messages to stdout instead, so that test runners will
suppress them during passing tests, and show them during failing tests.
It would be nice to have a place to write this method just once for the
Youtube and LTI mock servers, but we don't seem to have a place for code
as common as that.
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[
Fix bug when the user clicks on the video time-line either
before or after the specified end time, it jumps
to the very beginning of the video.
BLD-392
Fixes [BLD-456] and [LMS-1392], but making sure that we're always asking
XModules about their course_id (since the ModuleSystem has access to
that data).
