quassel 0.9.1

Update to 0.9.1, which is a 'mandatory' update for many of those using
the core part of Quassel. See http://quassel-irc.org/node/120.

Remove patches entirely as they are not recommended by upstream Quassel
or Qt.

Closes #23417.

Signed-off-by: Mike McQuaid <mike@mikemcquaid.com>