setup: reformat options argument
This makes things a bit more easier to manage IMO.
Differential Revision: https://phab.mercurial-scm.org/D3540
contrib: remove fixpax.py
This was used as part of bdist_mpkg. And we stopped using bdist_mpkg
after
db5084d27df5.
Differential Revision: https://phab.mercurial-scm.org/D3539