jsonalchemy: validator test fix

Signed-off-by: Jiri Kuncar <jiri.kuncar@cern.ch>
jsonalchemy: bug fixes

* Fix record tests when using '001' marc tag.

* Implement `_prepare_blob` method for json_reader to use the model
  field names when using a JSON input.

* Fix model inheritance when overriding fields.

* Fix validation when using models and override fields.

* Enhance `creation_date` field definition.

* PEP8 fixes.

Signed-off-by: Esteban J. G. Gabancho <egabancho@gmail.com>
jsonalchemy: model resolver fix

Signed-off-by: Esteban J. G. Gabancho <egabancho@gmail.com>
bibdocfile: fix for undefined docname in get_text

Signed-off-by: Johnny Mariéthoz <Johnny.Mariethoz@rero.ch>
previewer: PDFtk previewer

Signed-off-by: Adrian-Tudor Panescu <adrian.tudor.panescu@cern.ch>
annotations: initial commit

* Allow annotating any page.

Signed-off-by: Adrian-Tudor Panescu <adrian.tudor.panescu@cern.ch>
annotations: file attachments skeleton

* Can be enabled via the ANNOTATIONS_ATTACHMENTS configuration
  parameter.

Signed-off-by: Adrian-Tudor Panescu <adrian.tudor.panescu@cern.ch>
annotations: record document annotations

* Add infrastructure for adding targeted notes on records (e.g., on
  pages, figures).

Signed-off-by: Adrian-Tudor Panescu <adrian.tudor.panescu@cern.ch>
comments: annotations integration

* Integrates the record document annotations with the Invenio commenting
  facilities and PDFtk previewer.

Signed-off-by: Adrian-Tudor Panescu <adrian.tudor.panescu@cern.ch>
annotations: JSON-LD publishing

* Add JSON-LD publishing utilities for annotations and RESTful API
  helpers.

Signed-off-by: Adrian-Tudor Panescu <adrian.tudor.panescu@cern.ch>