D2090: fancyopts: add support for custom multi-arg opts in fancyopts.py

[dploch (Daniel Ploch)]

dploch added a comment.


  Friendly ping!  This is my first commit so I'm not sure if more information or changes are expected; please let me know if there's anything I'm missing.

REPOSITORY
  rHG Mercurial

REVISION DETAIL
  https://phab.mercurial-scm.org/D2090

To: dploch, #hg-reviewers, durin42
Cc: durin42, indygreg, mercurial-devel