make it working with django 1.6
initial work towards django 1.6
Merge branch 'master' of https://github.com/GeoNode/geonode into django1.6

Conflicts:
	geonode/contrib/services/urls.py
	geonode/documents/urls.py
	geonode/documents/views.py
	geonode/layers/urls.py
	geonode/layers/utils.py
	geonode/layers/views.py
	geonode/maps/models.py
	geonode/maps/urls.py
	geonode/maps/views.py
	geonode/people/urls.py
	geonode/proxy/views.py
	geonode/views.py
	setup.py
fix url imports and hashlib for django 1.6
add default value to map layer transparent
fixed proxy tests, thanks @ingenieroariel
add api url
save the layers even if the was is not available, by @ingenieroariel
ad a wcs links test to integration
update setup.py to geonode django1.6 forks
Merge pull request #1487 from simod/django1.6

Update to django 1.6