Bugfix done cards + Trelloscrum pattern without effort indication

Hi,

**fix 1:**
for some reason cards within the "finished list" haven't been recognized any more. I'm not exactly sure what caused the issue, seems like it was a refactoring in the `helper.js`. Anyway, the problem was that the cards from the finished list have not been retrieved and thus weren't taken into account when creating the statistics.

**fix 2:**
I noticed that your implementation of the trelloscrum pattern did not allow to have something like this `(3) Card title`. This is basically the case when the user doesn't specify any effort yet, tipically during the planning where I wouldn't like to manually add a zero effort like `[0]..` to any card. Thus I tried to adapt the regex to also account for this scenario.
_(Note that I don't really like my implementation, it's kind of the opposite of an elegant implementation, but I needed it very urgently and my programming fu isn't the best - being sunday evening ;). So I may come back and refactor this unless you have a better fix already at hand.)_