Corrected issue where forwardedChangesToRevert was used in change
forwarder. This implicated that the same changes where reverted twice
whereas the wanted behavior was the forwarded changes to revert should
be reverted once and then redone afterwards. Now, backwardOutput is used
which consists of the commands to redo the forwarded commands to revert.

Signed-off-by: Jakob Brandsborg Ehmsen <jakobehmsen.github@gmail.com>