Update devel/py-configargparse to 0.10.0.

pkgsrc changes:
o Get rid of VERSION variable and other PKGNAME hard-coding and use
  make(1) ``:tl'' modifier instead (no functional change intended)
o Use MASTER_SITE_PYPI instead of the full pypi URL.

Changes:
0.10.0
------
o Various misc bug fixes and improvements

(leot)