Remove status field from sandbox fixtures

make sandbox was broken. Now it is unbroken.
Handle cookies that contain strings

We have a broken "NING/1.0" bot crawling our customer's site that sends a quoted string here that deserializes to a unicode object.
Fix links for other GitHub repos in the docs
Merge pull request #1229 from patrys/patch-1

Handle cookies that contain strings
Merge pull request #1230 from grakic/patch-4

Fix links for other GitHub repos in the docs
Ensure "active" offers exclude those that are suspended

This required extending the offer factories to support setting the
start- and end-dates (looking forward to using FactoryBoy now).  Some
additional tests were added for the active manager.

Fixes #1128
Handle naive datetimes in offer message filtering fns
Remove autoslug fields from admin classes

They fail on the autodiscover call.
Ensure change password page requires authentication

Fixes #1231