WIP: add two more flash modes
After some discussion in photography group with @Flohack74 I will try to add two more flash modes. This might need some more work, and I am not sure if I know what I am doing ;-) but Florian said we may try it nevertheless.
Please feel free to comment or give suggestions or let me know if or why this will not work at all. I am more or less doing a copy-paste-alter job without c++ knowledge. So mistakes expected.