#652 - Fix for PP error when SlideShare urls contain querystring params

Brought in the SlideShare module which will take care of the querystring stripping
Temporarily pointing to my (@simong) repo in package.json till the fix
gets merged upstream.
fix outdated preview image on activity feed
#663 - Fix intermittent failure when importing users.
#664 - TincanAPI test failure fixes

* Replaced switch-case with if-elseif
* Fixed up unit tests by forcing collection before the tests
add revision back to the content body modified event
add unit test
Renamed `done` callback function in importUsers
Merge branch '664-tincan-failures' of https://github.com/simong/Hilary into 664-tincan-failures
Documentation improvements
Merge branch '652-slideshare-links' of https://github.com/simong/Hilary into 652-slideshare-links
Documentation changes and re-ordering of slideshare import
Merge pull request #621 from stuartf/activityPreviews

Activity shows old preview in activity stream after new revision has been uploaded