Imap-tools

decomposition to modules
remove typing dependency
add MailMessage.cc, MailMessage.bcc attrs
specify custom classes email_message_class directly
MailBox._uid_str change type check logic
!!! Change MailMessage attr return types: lists -> tuples
MailBox.fetch add mark_seen param
fix MailMessage.from_ bug when empty

new MailMessage.uid parse logic
functools.lru_cache for MailMessage properties
MailMessage.get_attachments() -> MailMessage.attachments
fix setuptools