Fix errors on entity (de-)serialization
Implement bulk import

Fixes EDOZWO-78
Implement pager for entity listing
Obtain relations and files from struct. metadata
Update autocomplete URL
Fix undefined index on child-entity listing
Implement configurable debugging output
Implement option to only bulk import entities for which metadata exists
Update README with ctools dependency
Harmonize entity title display
Align URI structure with regal API
Fix URL conflict between pager and entity view

Pager now uses query string parameter ?page=n
Fix superfluous API writes

Since parent/child relations are handled by the API, descriptive
metadata of the parent does not have to be updated with the child
relation. Cache is invalidated to force reload of structural metadata
from API.
Use remote IDs in URLs
Show entity serializations only in debug mode
Fix error on missing file entity
Fix urlencoding for autocompletion
Fix remote_id for imported entities
Add labels for display of linked data fields