courlan-1.4.0

• More robust FIND_LINKS_REGEX expression by @danishashko (#130)
• Maintenance: code hardening and modernization, more tests (#124, #125, #127, #131, #132)
• Breaking: UrlStore() parameter trailing renamed to trailing_slash
• Drop support for Python 3.8 and 3.9
• filter_links() and load_store() are now exported at the top level