Merge lp://qastaging/~jasperge/openlp/versenumbers into lp://qastaging/openlp

Hi Jasper - I think this must be your first merge request, right? Welcome onboard! It's always great to see new contributors!
As you probably know we are currently preparing for our 2.2 release, and are in a feature freeze, so your changes might not get merged until after 2.2 is released.

I did some testing of your branch and found an issue. For a song which had a verseorder like this: "C1 C1 V1 V2 V3" the footer looked like "Chorus, 1, 2, 3" for the first 2 slides (the chorus'es), but when I reached the 3rd slide with the first verse it changed to "1, 2, 3" - the chorus disappeared.

You also need to make some tests to prove that your code works as expected. Take a look at the existing tests under the "tests" folder for inspiration.

Hi Tomas, Yes and thank you!

The issue you found is actually a feature. :) The reason for this is, that if you have 5 verses for example with the chorus after every verse, you get a very long text: "1, Chorus, 2, Chorus, 3, Chorus, 4, Chorus, 5, Chorus". To be honest, I've adopted this from OpenSong and have no idea how (and if) other programs have implemented this. Ideas and suggestions are welcome.

I will have a look at writing tests.

A question that came to my mind after I submitted the merge request: should I store the verse numbers in the `raw_footer`? At the moment I change the title (the first element in the `raw_footer`) to include the verse numbers. But displaying the verse numbers is really only a display feature and not a property of the song. So I could leave the `raw_footer` alone. For the end user this shouldn't change a thing, but it seems the proper thing to do.