OSIS-799 Make function _create_proposal more generic
OSIS-799 Make function _create_proposal more generic

uclouvain/osis,uclouvain/osis,uclouvain/OSIS-Louvain,uclouvain/osis,uclouvain/osis_louvain,uclouvain/osis_louvain,uclouvain/OSIS-Louvain,uclouvain/osis_louvain,uclouvain/OSIS-Louvain,uclouvain/osis