Bill segmentation

Added a first version of bill segmenation (see https://renkulab.io/gitlab/luis.salamanca/democrasci_preprocwp1/wikis/Bill-Segmentation-in-the-Session-Overview-documents )

in the process I ended up deleting the data/logs/removed_duplicated_textlines.csv file. In case this gives a merge conflict you can delete it, as it will be generated again next time the corrected_xml04 is updated.