CYB-225 - Update to AngularJS 1.3.0

https://jira.ets.berkeley.edu/jira/browse/CYB-225
Merge pull request #114 from christianv/CYB-225

CYB-225 - Update to AngularJS 1.3.0
CYB-189 Refactor session initialization
* much cleaner session initialization (cleaner API)
* remove unused (and broken) action, and associated gem
Merge pull request #116 from coyote/new_current_user

CYB-189 Refactor session initialization
CYB-220 - Videos should show the date posted - front-end
CYB-220 - Videos should show the date posted - back-end

Timestamps as returned by the API should be in a JS friendly format, not as strings.

* Front end code from Christian
* Changing Attachment table's 'date' column to a Datetime, rather than a String
* Requires a (destructive) migration
* other than the type change, backend as submitted by Christian

Author:    Christian Vuerings <vueringschristian@gmail.com>
modified by Coyote (craig.a.cook@gmail.com)
Merge pull request #117 from coyote/date_video

Date video
CYB-226 Engagement Index should be frequently, automatically, updated
* renaming the old Canvas::ApiRequest service to simply "ApiRequest" service, and clean up of its code.
* using new 'keyword arguments' of Ruby 1.9-2.0+ in place of Hash arguments (Ruby 1.8- style).
* Does not complete ticket; done in two PRs to keep the code changes understandable.