Ignore e-mail addresses in Thunderbird recipient fields by default

[1ec5]

The To:, Cc:, Bcc:, Reply-To:, and Followup-To: fields in Thunderbird’s Compose Message window accept a combination of names and e-mail addresses. When AVIM is set to ignore e-mail fields, as it is by default, it should ignore anything between angle brackets in these fields but still allow adding diacritics outside of the angle brackets.