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

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 ","