Changed Django get params used in wms_links lookup to move url to defaults dict.  Prevents duplicate WMS links via repeated updatelayers calls
FGDC Topic Category extraction
Assigns TopicCategory to Layer using extracted metadata.
Added category_list to advanced search context for category filter
Added category filter
Added support for capturing multiple keywords from FGDC metadata.
added OL to search
added UI for search by extent
UI cleanup for extent search
added extent filter to search results page
Refactoring migrations.
Added the migration for adding the resourcebase_ptr_id field in layer.
Added the migrations to move layer stuff to base.
Some more steps added.
removed extra openlayers in favor of OL wrapped in ExtGeo
added geoexplorer JS packages in search templates and wrapped in Ext
Merge branch 'master' of https://github.com/GeoNode/geonode
Decode name value into localized string before get_or_create query.  Now prevents duplicate WMS download links due to changed bounding box in url
Intermediate commit for Simone.
Now resource_base is correctly populated with layers.