#671 - Allow for redirecting with the external auth strategies

Specifying a `redirectUrl` request parameter in the external
authentication strategies will redirect the user to that URL once they
return to the application. If no value is provided, `/me` will be used.

I also took the opportunity to streamline the external auth strategies
a little bit so we don't need to paste the complex passport boilerplate
in each strategy's REST file.

Currently supported strategies:
 * CAS
 * Facebook
 * Google
 * Shibboleth
 * Signed authentication
 * Twitter
#671 - Addressed Open Redirect issue in external authentication
Clearing redirectUrl cookie
#671 - Moved external authentication strategies to POST
Using object for upconfigConfigAndWait
Added a bunch of external authentication tests and improved CAS error handling
Bumping timeout for travis tests as the coverage seems to have slowed it down a bit
Merge branch 'master' into authentication-redirect

* master: (42 commits)
  Expose Google Apps domain in config feed
  change config.previews.dir to config.previews.tmpDir
  Uploading Travis CI logs to s3/travisci/logs/hilary/
  Uploading test logs to Amazon S3 when a TravisCI build fails on master
  Removed activity migration for 3.0.0 to 4.0.0
  Embeddable link test now uses mocked HTTP server
  Specify base directory, use gitVersion utility
  use the external oae-rest module
  (Release 5.0.0) Remove shrinkwrap
  (Release 5.0.0) Bump version
  Revert 5.0.0 due to issue with the npm-shrinkwrap
  (Release 5.0.0) Remove shrinkwrap
  (Release 5.0.0) Bump version
  Update notify-content-share.meta.json.jst
  Set grunt-contrib-jshint to latest
  (TravisCI) Remove global phantomjs to force 'npm install' to download it
  Followup on SQL3
  Fix getLastUpdated for configuration values
  (CQL3) Fix unit test failure
  (Issue 696) Migrate queries to CQL3
  ...
Authentication redirect follow-up

Various JSDoc cleanup
Merge pull request #671 from simong/authentication-redirect

External authentication doesn't redirect correctly