Fix for intermittent push unit test failures

Bug: The activties were being delivered on the websocket before we had
bound the `message` event listener.

Fix: Bind the event listener in the same process tick as we perform the
action for which we should receive a message on the socket.

The tests have also been cleaned up a bit as they were performing
unnecessary activity collections (push notification happens on routing,
there’s no need for aggregation/collection)
Fix broken push tests
Update README
Wrapping etherpad html with an UTF8 charset when generating preview images
(Gruntfile) Exclude node_modules of external oae-* modules
(package.json) Revert package.json bump to 6.5.0
Merge pull request #902 from mrvisser/exclude-nodemodules

(Gruntfile) Exclude node_modules of external oae-* modules
(Release 6.5.1) Bump version
(Release 6.5.1) Remove shrinkwrap
CSV Import fix

The csv module had some non-backwards compatible changes that were
failing the unit tests. This commit follows the new API which fixes the
tests
Merge pull request #661 from nicolaasmatthijs/issue-661

Update README for Cassandra 2.0
Missing space
Merge branch 'master' of https://github.com/oaeproject/Hilary
Merge branch 'etherpad-utf8' of https://github.com/simong/Hilary into etherpad-utf8
Merge pull request #897 from simong/intermittent-push-failure

Fix for intermittent push unit test failures
Add support for external logout

Each OAE authentication strategy can now expose a `logout` function
that will called when a user that authenticated with that strategy logs
out.

This has currently only been implemented for CAS
External authentication logout

 * Removed ctx from `strategy.logout`
 * Cleaned up CAS tests