plugin email invitation: fixed create/simpleCreate + invitee_name: - fixed invitationSimpleCreate signature - fixed nicknames settings in create - use async coroutines - guest jid is now stored (as a string), avoiding the need to check profile to retrieve it - invitee_name is now needed in invitationSimpleCreate

You'll find install instructions in documentation (see doc/installation.rst).

If you need help, come the SàT official XMPP room: sat@chat.jabberfr.org or join us with a web browser via https://chat.jabberfr.org/converse.js/sat@chat.jabberfr.org