When recording ChangeDescription entries for a change in ownership on

a review request, we rely on User.get_absolute_url(). This is defined

globally for users via settings.ABSOLUTE_URL_OVERRIDES, but the value

doesn't take into account Local Sites, and on RBCommons we don't have

this set at all, meaning this function is not available on User.
To address this properly, ChangeDescription.record_field_chnage()

now takes an optional build_url_func(), which can be used to let a

caller handle URL computation for the objects. This is specified by

OwnerField to compute a URL relative to the Local Site or global site

for the parent review request.

Removed the ABSOLUTE_URL_OVERRIDES and reproduced the original problem

publishing. Verified that this patch fixed that, and generated a correct

URL for both the global site and Local Site.
Tested this on RBCommons as well.