utils: etree to dict translation reorganization

* Adds xmlhelpers to utils to handle custom XML.

Signed-off-by: Pedro Gaudêncio <pedro.gaudencio@cern.ch>
Reviewed-by: Javier Martin Montull <javier.martin.montull@cern.ch>
utils: import json from arxiv api

* Adds API to import JSON data from http://export.arxiv.org with a
  given ArXiv ID.

Signed-off-by: Pedro Gaudêncio <pedro.gaudencio@cern.ch>
Reviewed-by: Javier Martin Montull <javier.martin.montull@cern.ch>
arxiv: initial Flask extension commit

Signed-off-by: Jiri Kuncar <jiri.kuncar@cern.ch>
records: API for database querying with DOI

* Adds API to query the database with a DOI.

Signed-off-by: Pedro Gaudêncio <pedro.gaudencio@cern.ch>
Reviewed-by: Javier Martin Montull <javier.martin.montull@cern.ch>
Reviewed-by: Jiri Kuncar <jiri.kuncar@cern.ch>
travis: less verbose output

Signed-off-by: Jiri Kuncar <jiri.kuncar@cern.ch>
installation: requirement addition for six library

Signed-off-by: Jiri Kuncar <jiri.kuncar@cern.ch>
arxiv: docs entry addition

Signed-off-by: Jiri Kuncar <jiri.kuncar@cern.ch>
docs: css theme overrides

Signed-off-by: Jiri Kuncar <jiri.kuncar@cern.ch>
assets: require.js + uglify.js

* Updating webassets and Flask-Assets to 0.10-dev.
  BROKEN see: https://github.com/miracle2k/flask-assets/pull/67

* Hacking the assets extension to remove the initial "/" to js modules
  otherwise r.js is confused.

* Grouping the invenio.js with bootstrap.js.
  It's a PROOF OF CONCEPT! THINGS ARE GONNA BREAK!!

* Using require.js in dev and almond.js in production.

Signed-off-by: Yoan Blanc <yoan.blanc@cern.ch>
base: using bootstrap 3 via require.js

Signed-off-by: Yoan Blanc <yoan.blanc@cern.ch>