Rename facet value string
Rough implementation of faceting
Surrender to inevitability and move all models to core module.

This allows us to get rid of the mutable config that registered models
for generic JSON conversion and is, anyway, consistent with having the
type string definitions in core anyway. Keeping the controllers, views,
and routing in separate modules should keep the benefits in terms of
incremental compilation.
Merge branch 'master' into portal_integration