jsonalchemy: validation fixes

Reviewed-by: Jiri Kuncar <jiri.kuncar@cern.ch>
Signed-off-by: Esteban J. G. Gabancho <esteban.gabancho@gmail.com>
uploader: typos fixes

Reviewed-by: Jiri Kuncar <jiri.kuncar@cern.ch>
Signed-off-by: Esteban J. G. Gabancho <esteban.gabancho@gmail.com>
records: better PID list

Reviewed-by: Jiri Kuncar <jiri.kuncar@cern.ch>
Signed-off-by: Esteban J. G. Gabancho <esteban.gabancho@gmail.com>
uploader: files to link addition

* Adds new option for linking files with record via custom FFL MARC
  field.

* Adds `legacy` step to uploader insert worflow for filling-up "bibxxx"
  tables.  (addresses #1772)

Signed-off-by: Jiri Kuncar <jiri.kuncar@cern.ch>
previewer: addition of support for Documents

Signed-off-by: Jiri Kuncar <jiri.kuncar@cern.ch>
uploader: support for relative document paths

* Allows specifying relative paths in FFT tags.  (closes #1191)

Signed-off-by: Jiri Kuncar <jiri.kuncar@cern.ch>
oaiharvester: record splitting improvement

* Improves the splitting of records from OAI-PMH requests to also
  handle the case of MARCXML from other Invenio instances.

* Defers the splitting logic to a XML parser and moves some utility
  functions to a new utils file in the new module structure.

* Adds tests for these utility functions.

Signed-off-by: Jan Aage Lavik <jan.age.lavik@cern.ch>