Clean useless code + update version to 20.03

CHANGES.txt

INSTALL.TXT

README.md

apps/maarch_entreprise/css/doctype_levels.css

apps/maarch_entreprise/css/styles.css

apps/maarch_entreprise/indexing_searching/TemplatePrint.pdf

apps/maarch_entreprise/indexing_searching/file_iframe.php

apps/maarch_entreprise/indexing_searching/manage_query.php

apps/maarch_entreprise/lang/en.php

apps/maarch_entreprise/lang/fr.php

apps/maarch_entreprise/lang/nl.php

apps/maarch_entreprise/merged_css.php

...rch_entreprise/tools/referentiel/code_postaux_v201410.csv

core/class/class_security.php

migration/20.03/2003-postScript.sql

modules/attachments/css/module.css

modules/attachments/js/functions.js

modules/attachments/lang/en.php

modules/attachments/lang/fr.php

modules/attachments/lang/nl.php