API: Allow passing callables to AnyUrlField.register_model() for lazy evaluation
Add AnyUrlField.__deepcopy__ to fix Django < 1.7 issues

Without this method, the querysets are not evaluated again,
preventing page updates to be visible. This is visble for example when
SITE_ID is a threadlocal, and the queryset uses it.

Ticket: https://code.djangoproject.com/ticket/19298
Update version and changelog for 1.0.12
Merge branch 'v1.0.x'