[request] Ensure base_url() always has a trailing '/' (closes #3955093)
Just as an example, cubicweb.ajax.js is clearly written under the
assumption that BASE_URL/baseuri() - which simply contains req.base_url() - has a
trailing /.
from datetime import datetime
for rtype in ('cw_support', 'cw_dont_cross', 'cw_may_cross'):
drop_relation_type(rtype)
add_entity_type('CWSourceSchemaConfig')
if not 'url' in schema['CWSource'].subjrels:
add_attribute('CWSource', 'url')
add_attribute('CWSource', 'parser')
add_attribute('CWSource', 'latest_retrieval')