Remove semantically meaningless sections from course.xml by moving their attributes onto the contained element. If there is more than one contained element, turn the section into a sequence. Also handles includes

Also:
Render all XModuleDescriptors in the cms the same way
Default them to editing raw xml, if there is no specific module for them

Roundtrip HTML module editing working in the CMS

Victor/xml testing

TODO:
  - support picking a different course name
  - make it use current module rendering path, get that working.

* wasn't passing namespace properly in parse_course_file

* Separate out all xml processing code from django code
* Preparing to move the content parsing parts into common/lib/xmodule (?)

bugfix: lcp score can apparently be 0/0

Victor/show student state

* use clearer names for the two status strings passed to js
* add functions to do canonical conversion of progress to js string
* fix updating bug in sequence.coffee
* add some todo comments and other docs to make future expansion easier

* change bottom border of links:
  red for not started
  yellow for in_progress
  green for done

* This should probably be designed at some point.
* Obvious problems: the yellow is not very visible, and lots of people are
  red/green color-blind.

Fix render of lms index with no chapter or section.