Portfile variants vs. subports recommendation

[Jason Mitchell]

Hello,

For projects with several forks, i.e. more than stable and devel, what
is the preferred Portfile treatment?  Consider git-flow, which uses the
canonical nvie GitHub (GH) repository that is inactive.  Of nvie's ~1000
forks, at least 2 are useful:

  - petervanderdoes/gitflow: AVH Edition
  - datasift/gitflow: HubFlow (GH tweaked, different git trigger)

Options considered:

 1. git-flow Portfile w/ nvie as default (variant), w/ +avh +hubflow;
    each variant conflicts with others
 2. git-flow Portfile w/ separate named subports, e.g. 
    git-flow-{nvie,avh,hubflow}; nvie and avh conflict
 3. combination of #1 & #2, w/ variants on default port set depends

Based on gnuradio, it seems #2 is preferred, then let the end-user
decide.  #2 also seems easier to make gitflow variants directly on git.

Thanks,
-jason

Disclosure:  I submitted the initial git-flow Portfile.