Compare bare JID of from attr in roster update. @teseo's fix was too specific
and tailored for a misbehaving server (servers shouldn't be sending from the
full JID in a roster push).
* Fixed a bug in the process which prevented "to" contacts from being shown as
existing.
* Add "to" or "both" as classes on the contacts to indicate their
subscription status.
* Delete roster handlers in tearDown method to avoid them being registered
multiple times.