encrypt and decrypt GPG messages in a thread, and call a callback when it's finished (sending a message is now asyncronous). Fixes #4445

[pvgoran] use correct function to get custom status message. Don't ask it if there is a default message configured. Fixes #4762

Removed premature triple-dots in contact's status message (MUC). Fixes #4741 (caused by changeset [11042]).

allow ignore_unknown_contacts, send_os_info and log_encrypted_sessions to be set per_account in ACE. Fixes #4730