Hi,
I found some time to add some more features, now you can add/edit/remove single periods of current projects.
You find the deb-file of this testing version in the first post of this thread.

To open the edit mode you have to double click on the project you want to edit.

Before I'll send it to QA I would be pleased, if someone can test the functionality and give a feedback (bugs?)

Any other feedback still welcome!