Maintenance of this repository upstream (opatut/dudel) has stopped in favor of a complete rewrite of the software that does more things right™.
The rewrite is (for now) called "Dudel 2" and is still in a very early development phase. It will be open sourced once most architectural decisions are made and the basis is complete for putting features onto it.
If you want to join me in developing Dudel 2, please email me (see my github profile for the address) and I can provide you with more information.
Dudel is dead, long live dudel.
If you still want to push this project further, you may of course simply select an issue, comment on it that you're on it, and start working. I am still accepting pull requests, I just don't have much time myself for hacking. Bugfixes and security improvements are of course always welcome, however, new features should probably not be added to this version anymore.