Looks good to merge, thanks! :-)

That's strange, fixed it.

Your last commit message is lying: the diff only contains one of the two changes.

https://bitbucket.org/SilvanS/fd-dev/commits/0c71559b5f6dae358cd816e79bc0cd60abd465e2?at=default

Right, I messed up the order of the parameters.

Two more comments, this time more important. :-) (I think with the latest change
all reported times should be 0 because we count things negatively and change all
negative values to 0?)

Done with addressing them.

I've made some more comments.

From my point of view it is.

I addressed all comments, is this ready for merging?

I'm done with my comments.

Looks good to me. I left one minor comment.

Pull request: https://bitbucket.org/SilvanS/fd-dev/pull-requests/33/issue763/diff

Currently, CountdownTimer objects, if passed to an output stream, print the
elapsed time and not the remaining time, which at least Malte and I found
surprising. We want to change the Timer class to return a simple wrapper of
double that can be used as a double or formatted for printing. CountdownTimer,
using the Timer class internally, will do the same for both of its methods
"get_elapsed_time" and "get_remaining_time".