Merge branch 'tb/delimit-pretty-trailers-args-with-comma'

The feature that allows --pretty='%(trailers)' to take modifiers like "fold" and "only" used to separate these modifiers with a comma, i.e. "%(trailers:fold:only)", but we changed our mind and use a comma, i.e. "%(trailers:fold,only)". Fast track this change before this new feature becomes part of any official release. * tb/delimit-pretty-trailers-args-with-comma: pretty.c: delimit "%(trailers)" arguments with ","