Store share DocumentSource parameters in the knowledge base together with the DocumentSourceReference.

Currently, we store DocumentSourceReference items in the knowledge base in order to be able to trace back the annotated documents and display the annotations.

The problem is that the DocumentSourceReference stores only the document source name, but not also the DocumentSource's configured parameters. Some examples are:

• FilesystemDocumentSource: when importing such a document source from the KB, one could provide another directory than the initially configured one and relative directory paths pointing to annotated document would not make sense anymore or will point to completely different documents.

• XWikiDocumentSource: when importing, one could provide a different URL and end up trying to display annotations of completely different documents. The user name and password could also be important but those should not be stored for security reasons and can be provided at each import.

Thus, we need to differentiate between persistent (directory path, URL, anything defining location of the documents) and transient (username and password, private key, etc.) configuration parameters and store the persistent ones within the DocumentSourceReference in the KB.

When importing a document source, the persistent parameters together with their values will be imported as well and a consistent state will be preserved for new and existing annotations.