Store upgrades: access entries by resource, config, better permissions.
Require work_uri for work-related methods.
Merge branch 'master' of github.com:commonsmachinery/catalog into store-updates
Use entry uris in the celery wrapper.
Merge remote-tracking branch 'origin/master' into store-updates

Conflicts:
	backend/catalog/celery.py
	backend/catalog/store.py
Lock entries before updating.
Misc fixes, mostly related to moving user IDs to URIs and adding rdf:type to entries.
Limit the list of properties that we can update
Delete works from public store, if visibility changed to private.
Remove CatalogSource and ExternalSource entry types
Use thread-local instances for database-connected objects
Return thread-local connection directly in Task
Merge remote-tracking branch 'origin/frontend-call-wrapper' into store-updates
[backend] error handling, new query API, and missing DB params to RedisLock
[frontend] Update to new backend API
Merge pull request #8 from commonsmachinery/store-updates

Store updates
[frontend] Timeout on backend task response after 15s