Notifications that are of the same type but are separated by a groupable
notification of a different type are now considered groupable. For
example:
favorite 1 (status 1)
reblog 1 (status 1)
favorite 2 (status 1)
reblog 2 (status 1)
mention 1
reblog 3 (status 1)
will be grouped into:
favorite 1, 2 (status 1)
reblog 1, 2 (status 1)
mention 1
reblog 3 (status 1)
Also, copy the state between screens, so e.g. expanding a status in the
timeline and then opening that conversation already has that status
expanded.
This intentionally doesn't store the sensitive attachment visibility
state, since showing text when not necessary is less dangerous than for
images. (Possibly a preference for this in the future?)
Closes#55
Shadowfacts