Opening multiple etherpads on the same view is inconsistent

[codeofmochi]

Etherpad will always open a single one among them.

This is probably caused by the server sending a different cookie value for each pad, the browser thus overwrites the previous cookie value. The cookie value can be a comma-separated list of session IDs, so we need to remember which ones to send (see getSessionOfAuthor from Etherpad API). We can also implement the cleanup mechanism as in #6 after the response.