Adds and uses a modified_by property in models/work.py
This property is used to display the user who last edited the work in the document viewer.
Fixes author being set on every edit.
Also edited the style-sheet to fix issue i128.
Patch by: Lennard de Rijk
# Want to get everything from the 'normal' models package.
from django.db.models import *
# The GeoManager
from django.contrib.gis.db.models.manager import GeoManager
# The GeoQ object
from django.contrib.gis.db.models.query import GeoQ
# The geographic-enabled fields.
from django.contrib.gis.db.models.fields import \
GeometryField, PointField, LineStringField, PolygonField, \
MultiPointField, MultiLineStringField, MultiPolygonField, \
GeometryCollectionField
# The geographic mixin class.
from mixin import GeoMixin