Group phabricator notifications

This extension makes the phabricator notifications be grouped per task, so that they are less noisy to read.

You can expand the task to see the actual changes in it, or mark as read without even going to the task.

Applies to all phabricator.*.* and *.phabricator.* urls.

Source is at https://github.com/joakin/group-phabricator-notifications