Cleaning up messes from hurried upstream merge

* Restore the temporary use of edx_sga to our CMS advanced components
  list
* Uncomment lines commented out (and then forgotten) during unit test
  debugging
Remove commented code

These lines are remnants from debugging during conflict resolution,
following the merge from upstream.
Merge PR #98

from 'stv/bugfix_bad_merge_conflict_resolutions'
into 'master'