Various tidyups from pyflakes.

Mostly make the imports explicit, also avoid a variable name clash.

Change-Id: Ida06e869a3b4b414ee62d427af5c5e4828ad006e
Also reset the media-consent group.

Change-Id: I4c28e5158b2324c401b481f8104b466b24ed7347
Use the same gidNumbers as puppet where possible

This avoids puppet and the reset script here fighting over which one
is 'right' about the gidNumbers.

Change-Id: Ibc28dc5c0ec5981f40bf009ed54e5b5e3a382ded