Incomplete: trying to get plurals working.  Uncovering some PNOde memory management issues.
Got plurals dumping the arguments inline (no curly brackets or commas).  Fixed overrelease problem.  Looks like confusion over who retains is causing a big over retention problem.  Fix eventually.
Got plurals working (by just copying all the arguments, no commas, no {..}).
Whoops: each value is coming back in it's own {..}!
Looks plurals are working superficially.  Probably there are major over retention problems.  This needs to be explored systematically.
Fixed a bug in explicit @prose matching.
Merge branch 'feature/plural-phrases' into develop