Updated topics.py to correctly create the nodecache from latest KA API.

Updated nodecache and topics.py.

Updated Video navigation for new keys.
Bug fix: Khan Academy had removed related videos from exercises data.

Now retrieved via separate API call.
Updated topics.py to correctly download all topic data.

Also now generate knowledgemap data, and download icons.

Missing icons are replaced by the default icon.
Script to pull latest Khan-Exercises repository.

KA Lite platform is not currently compatible with latest exercises.
Remove knowledgemap utils - this functionality is now within topics.py
First pass at converting scatter view to d3.

Original functionality replicated - now with user name hover, as well as click summary tooltip.

TODO:
* Replicate for timeline view.
* As all data has been retrieved through API, only refresh graph on axes change.
* Prettification.
Timeline view now switched over to D3.

Line plots highlight when appropriate legend is mouseovered.

TODO:
*Reduce y-axis options, and test all x-axis options.
*Integrate new activity reports into timeline.
*Use Raphael to give IE backwards compatibility.
Clean up of cruft.

TODO:
See last commit.
resolve sync warnings
Merge remote-tracking branch 'upstream/develop' into IDOC_coach_reports_jQuery

Conflicts:
	kalite/templates/coachreports/timeline_view.html
migrate to updated schema
removing cruft
Merge pull request #2 from bcipolli/IDOC_coach_reports_jQuery

Merge to develop, remove a bit of cruft.
update for subtitles as well.
Merge branch 'develop' into topicfixing

Conflicts:
	kalite/templates/topic.html
	kalite/utils/topics.py
updated scripts for pruning unknown exercises.
fixing small bug made apparent by exercise-eliminating.
Several tweaks in the Windows scripts
Removal of merge conflict "HEAD" items.

Moving endjs block out of content block to prevent repetition of graphs.
Fix PORT