(This revreq already got a "ShipIt" from David Trowbridge; awaiting integration upstream)

Fixes passing parameters to Nose when running tests.

./manage.py captures any parameter passed before an optional "--", so
running:

./manage.py test -s

to pass the -s to nose (to make it not capture stdout) doesn't work,
and manage.py dies with a "no such option" error. With this fix, this
works:

./manage.py test -- -s

Reviewed at: http://reviews.review-board.org/r/995

Ran ./manage.py test -- -s and nose ran without capturing stdout.