base: new Subjects KB

* Adds Subjects KB (used by deposit form).

* KB loading small enhancement to support matching of kb files
  independently of capitalization.

Signed-off-by: Javier Martin Montull <javier.martin.montull@cern.ch>
config: add CELERY_ACCEPT_CONTENT

* Adds the config variable CELERY_ACCEPT_CONTENT in order to
  specify the only accepted content for Celery workers.

Signed-off-by: Jan Aage Lavik <jan.age.lavik@cern.ch>
deposit: arXiv extra mapping fields addition

* Adds extra fields from arXiv (same as in oaiharvest).

* 980__a: 'arXiv', 'Citeable'.

* 65017__a: arXiv categories

* 65017__2: 'INSPIRE' and 'arXiv'.

* 269__c: preprint date from arXiv.

* 037__: 9:'arXiv', a: arXiv id, c: arXiv categories.

* 035__9: 'arXiv'.

* 530__b: 'arXiv'.

* Adds language field only if it's not english.

* Adds a space after the comma in the author's name.

Signed-off-by: Pedro Gaudêncio <pedro.gaudencio@cern.ch>
deposit: wrong mapping on conference info

Signed-off-by: Pedro Gaudêncio <pedro.gaudencio@cern.ch>
deposit: deposition title source in MarcXML

* Adds 'CrossRef' or 'arXiv' as the title source in 245__9 field.

Signed-off-by: Pedro Gaudêncio <pedro.gaudencio@cern.ch>
deposit: nonpublic note length and FFT fields fix

* Corrects nonpublic note lenght and FFT fields mapping.

Signed-off-by: Pedro Gaudêncio <pedro.gaudencio@cern.ch>
deposit: multiple URLs mapping to FFT

* Adds multiple URLs to the FFT field.

Signed-off-by: Pedro Gaudêncio <pedro.gaudencio@cern.ch>
deposit: arXiv journal names to INSPIRE mapping

Signed-off-by: Pedro Gaudêncio <pedro.gaudencio@cern.ch>
deposit: arXiv categories to INSPIRE mapping

* Adds arXiv to INSPIRE categories knowledge base and maps them.

Signed-off-by: Pedro Gaudêncio <pedro.gaudencio@cern.ch>