global: translation fixes
- Adds configuration file for message extraction.
- Extracts messages from source code files.
- Usage: python setup.py extract_messages -k '_(' \ -F mapping.cfg -w 100 --input-dirs invenio \ -o invenio/base/translations/invenio.pot --sort-output
Signed-off-by: Eirini Psallida <eirini.psallida@cern.ch>
Reviewed-by: Jiri Kuncar <jiri.kuncar@cern.ch>