parse_mailboxes: accept extra text after <...> address

parse_mailboxes: accept extra text after <...> address

The test introduced in this commit succeeds without the patch to Git.pm
if Mail::Address is installed, but fails otherwise because our in-house
parser does not accept any text after the email address. They succeed
both with and without Mail::Address after this commit.

Mail::Address accepts extra text and considers it as part of the name,
iff the address is surrounded with <...>. The implementation mimics
this behavior as closely as possible.

This mostly restores the behavior we had before b1c8a11 (send-email:
allow multiple emails using --cc, --to and --bcc, 2015-06-30), but we
keep the possibility to handle comma-separated lists.

Reported-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: Matthieu Moy <Matthieu.Moy@imag.fr>
Signed-off-by: Junio C Hamano <gitster@pobox.com>