Import calendar title form iCal files. Fix #111 and Fix #123 (again)

Add no description placeholder on events without descriptions. Fix #123
Use calendar name of iCal file to prefill calendar name on imports, use cozy-ical 1.1.4 .
Fixes in sendmail confirm, during import and to maintain sending email list accurate with mails actually sent by the server.

Fix tests and avoid rebase messup of previous PR.
I am not sure of this change. What is the use case you want to cover, that isn't?