clang format single line if

I noticed that Bruno and Robert prefer single line ifs (anybody else?). This wasn't possible last year. Now we can switch if you want.

First we need merge !593 (merged) otherwise you will have too many rebase conflicts. I can rebase it any time. That's just two commits.

If you feel like exploring other clang format options, go ahead :)

I notice that else is never in a single line. Looks like this year they have no option for that.